Repair 7

There are two oxygen or O2 sensors in the exhaust system on the 1995 Chevy Astro van. The process of changing the O2 sensors is the same whether it is the upstream or downstream sensors that you need to change, except that the location is different. These O2 sensors are critical to the proper operation of the fuel system and performance of the engine in your van. If you have a bad sensor, change it right away to correct drivability issues, hard stats and poor fuel mileage.

Instructions

1

Raise the front of your Chevy Astro with a jack and support it under the frame rails with a set of jack stands. Remove the jack once the van is securely on the stands.

2

Locate the O2 sensors from under the van. The upstream sensor threads into the exhaust pipe coming down from the engine manifold. It is on the inside edge of the pipe, closest to the engine block. The downstream O2 sensor is in the exhaust system just forward of the catalytic converter.

3

Determine which sensor you need to change, and position yourself below it. Locate the wiring harness coming out of the back of the top of the sensor and follow it up to the connector where the sensors harness and the vans wiring harness join. Disconnect the two halves of the connector by releasing the locking tab and pulling them apart.

4

Remove the O2 sensor from the exhaust pipe using an O2 sensor socket and ratchet to turn the sensor counterclockwise until it is free from the threads. Discard the old sensor and install the new one into the threaded hole on the exhaust pipe using your hands to get it starter. This will help prevent cross threading.

5

Tighten the O2 sensor with your O2 sensor socket and ratchet. Run the wiring harness connector from the new sensor up to the connector on the vans wiring harness. Push the two halves of the connectors together until the locking tab engages. If you are replacing both sensors, move to the other sensor and repeat the process.

6

Raise the front of your Astro off the jack stands with a jack. Remove the stands from under the van then lower the jack, setting the van back on the ground. Test run the engine to verify the sensors are functioning properly.

Volkswagen uses a camshaft position sensor on the 2002 Passat sedan to relay information about the camshaft position and engine speed to the electronic control module to determine ignition timing and fuel injection synchronization. Located on the cylinder head behind the upper timing belt cover on the 1.8-liter engine, the sensor is accessible for removal and replacement. Replace the sensor using basic hand tools.

Instructions

1

Locate the cam position sensor electrical connector on the timing belt cover just to the left of center of the engine. Unlock the connector retaining tab and pull the connector off the sensor.

2

Unlock the upper timing belt cover retainer clip at the top-right corner of the cover. Pull the top of the cover away from the engine slightly and disengage the upper cover from the tab in the lower cover. Lift the upper cover straight up and out of the engine compartment.

3

Remove the two camshaft sensor retaining bolts using a ratchet and socket. Pull the old sensor off the engine.

4

Make certain the tab on the faceplate on the end of the camshaft is properly indexed in its detent. Install the new sensor on the engine. Install the two sensor retaining bolts and torque them to 88 inch-pounds using an inch-pound torque wrench and socket.

5

Position the upper timing belt cover on the engine. Engage the tab in the lower timing belt cover with the slot in the upper timing belt cover. Snap the upper cover into place. Install the camshaft sensor electrical connector and ensure the retainer locks in place.

The EGR sensor is an automotive engine component designed to work with an exhaust gas recirculation system. Exhaust gas recirculation systems are part of many newer makes of automobiles, which must comply to more stringent environmental standards. The EGR sensor detects temperature and oxygen levels and determines whether the system is functioning properly.

Benefits

An EGR system offers two primary benefits to an automobile engine. The primary benefit is a reduced level of environmentally damaging emissions. The second benefit is a more efficient use of fuel, leading to better energy efficiency and more thorough combustion.

How EGR Systems Improve Engine Systems

An automotive engine without an EGR system releases gaseous emissions with hydrocarbon waste that has not been fully consumed by the combustion process. An EGR system recycles this partially combusted waste gas back into the combustion system to be used a second time for an overall cleaner emission.

EGR Sensor Warning

An EGR sensor fault warning on the vehicles indicator panel can indicate either that the sensor itself is damaged or that the exhaust gas recirculation system is not functioning within factory designated parameters. The best way to tell the difference between the two potential problems is to take the vehicle in for maintenance and have the sensor replaced.

Replacing the mass air flow sensor on your 2000 Buick 3.8-liter engine is relatively straightforward. The MAF sensor sits on top of the throttle body just above the air intake. The MAF sensor is a flat, plastic piece held in place with several screws and has an electrical connector attached to its left side. Replacement OE MAF sensors are available through the dealer and aftermarket replacements are available from most auto-parts stores.

Instructions

1

Open the hood of your Buick and locate the throttle body on the front of the engine. The air intake hose attaches to the front of the throttle body, making it easy to identify.

2

Disconnect the electrical connector from the end of the sensor by lifting the locking tab on the connector, then pulling it straight off the sensor. Locate the two screws on the top of the sensor--they are at opposite corners--and remove them with a Torx screwdriver.

3

Lift the MAF sensor straight up and away from the throttle body. Discard it and position a new MAF sensor on the throttle body, aligning the screw holes in the sensor with the threaded holes on the throttle body.

4

Install the two Torx-head retaining screws through the MAF sensor and into the throttle body. Tighten them with a Torx screwdriver, then push the electrical connector onto the end of the new sensor, making sure the locking tab snaps in place.

Cars need to breathe. Too much or too little air will cause big problems for your engine. Make sure you know what a remanufactured air flow sensor is, how it helps your vehicle breathe and when you may need one.

Air Flow Sensor Basics

The air flow sensor (AFS) measures how much air enters the engine on vehicles that have an electronic fuel-injection system. The sensor allows the vehicle to let more or less air into the engine, which controls idle speed and acceleration.

Remanufactured Definition

A remanufactured part is different from a rebuilt part. When you rebuild a part, you only replace the broken pieces. When something is remanufactured, the entire piece, called the core, is taken apart. All pieces are then cleaned, repaired or replaced.

When Your AFS Fails

If your vehicle begins to stall, misfire or accelerate slowly or not at all, you might need to replace your AFS. In this case, a remanufactured sensor will cost less than a new one. Have your vehicle checked by a certified mechanic before buying or trying to replace it yourself.

The 1997 Mazda Protg has a single oxygen sensor threaded into the exhaust manifold. When the sensor fails, it will trigger the "Check Engine" light on your cars instrument panel, and your cars gas mileage will substantially decrease. If you want to avoid losing money at the gas pump, purchase a new sensor from an auto parts store and replace it at home.

Instructions

1

Raise the Protg with a jack and secure the car on jack stands. Locate the oxygen sensor threaded into the exhaust manifold. The exhaust manifold is located beneath the intake at the base of the engine and is connected to the exhaust pipe. The oxygen sensor resembles a spark plug threaded into the manifold with an electrical wire connected to the top.

2

Pull the electrical connection apart to disconnect the wiring harness from the sensor. Remove the oxygen sensor from the manifold with a wrench.

3

Coat the new sensor threads with anti-seize compound. Insert the new sensor by hand. Tighten the sensor with the wrench. Push the electrical connection together until it locks.

4

Raise the car slightly with the jack. Remove the jack stands and lower the jack to return the car to the ground.

The 3.0-liter V-6 engine of the 1996 Nissan Maxima contains three oxygen sensors in the exhaust system. There are two upstream sensors in the front pipe just below the manifold flanges, and theres a third sensor down after the catalytic converter. Auto parts stores can determine which sensor has failed by reading the "check engine light" code the sensor has tripped. Most will perform this service for free in order to sell the parts to the customer.

Instructions

1

Apply the parking brake of the 1996 Nissan Maxima.

2

Hoist the front of the vehicle on one side with the car jack high enough to place a jack stand under the front frame rail. Repeat this for the other front side so the entire front axle of the car is elevated.

3

Put on the safety glasses. Locate the sensor being replaced by crawling under the vehicle. One sensor is located in the drivers side front pipe up near the manifold, another is in the shorter pipe (closer to the firewall) on the passengers side front pipe assembly, and the downstream sensor is located after the catalytic converter near the center of the undercarriage.

4

Disconnect the plug of the oxygen sensor from the plug of the harness.

5

Place the wire of the sensor through the opening of the 22-mm box-end wrench or in the slot of the O2 sensor tool. Place the wrench or tool onto the hex-head of the sensor.

6

Turn the wrench or tool (with a ratchet) to the left to remove it from the O2 sensor port. The sensors only have four to five threads, so once loosened, the sensor will quickly come out of the port.

7

Thread the replacement sensor into the port by hand. Tighten it with the wrench or tool and ratchet. Be caul not to overtighten the sensor. The threads are delicate and can be easily stripped. Tighten it snug only.

8

Connect the plug of the replacement sensor to the harness plug.

9

Collect the tools and other material from under the Maxima before lowering it to the ground.

Oxygen sensors provide information to the engine computer used to adjust the fuel mixture for efficient engine operation. There are two basic types of oxygen sensors and the sensors are used in two locations in many vehicles.

Unheated

Oxygen sensors create their own electricity, but must be hot to do so. Older oxygen sensors are unheated, relying on heat from the engine exhaust to warm the sensor. Unheated oxygen sensors are easily identified as they have one or two wires connected to the sensor.

Heated

Automobiles started using heated oxygen sensors in the 1990s; these oxygen sensors have an electrical heating element to warm the sensor. The advantage of heated oxygen sensors is they operate more quickly at startup than unheated sensors. Heated sensors have three or four wires connected to the sensor, with the added wires being used to operate the heating element.

Front and Rear

Vehicles manufactured from the mid-1990s have oxygen sensors located in the exhaust system above and below the catalytic converter. The two oxygen sensors are used to determine changes in the exhaust gases after they have passed through the converter. If the system does not note a change, a dashboard light will indicate a problem to the driver.

The common engine in the Chevy Cavalier is the 2.2 liter four cylinder. A few models have a 2.4 liter engine. Both engines use two oxygen sensors. Oxygen sensors read the amount of air and burned fuels in the exhaust system and transmit that data to the engine management computer through voltage. The computer then adjusts the ratio of air and fuel to lower the pollution in exhaust. When the sensor fails in the Cavalier, the computer ignores it and makes its own adjustments, which can cause more pollution, less gas mileage or both.

Instructions

1

Locate the oxygen sensor that needs replacing. If youre replacing the front one (upstream), you can access it in the engine compartment by lifting the hood. If you are replacing the rear sensor (downstream), youll need to lift the Cavaliers front end with the floor jack and support it safely and securely onto the jack stands. The front sensor is located in the front lower center of the engine and screwed into the header pipe. The rear sensor is located in the exhaust pipe near the catalytic converter. Put on safety glasses if you crawl under the Cavalier.

2

Locate the wire harness to the oxygen sensor. Use the flathead screwdriver to press in on the clip lock of the plug on the oxygen sensor wire and separate it from the wire harness.

3

Spray a liberal amount of penetrating oil on the threads of the oxygen sensor and allow the oil to soak in.

4

Place the box end wrench or socket onto the oxygen sensor and turn it counterclockwise to unthread it from the exhaust pipe. Remove the sensor.

5

Thread the new sensor into the oxygen sensor porthole in the exhaust pipe and tighten using the wrench or socket and a ratchet. Do not overtighten. Make sure its snug, but it is easy to strip the threads on the oxygen sensor so be caul.

6

Plug the oxygen sensor wire back into the wire harness and secure the wire so it does not dangle.

7

Remove the tools and either lower the vehicle or close the hood.

The 1995 Plymouth Voyager van uses an oxygen sensor to monitor the levels of oxygen in the exhaust. The sensors reading tells the Voyagers engine computer how to modify the air/fuel mixture for maximum fuel efficiency and minimal pollution. A failing sensor will illuminate the "Check Engine" light on the Voyagers instrument panel; it will also cause the Voyager to idle poorly and to use more fuel than necessary. To avoid wasting money on extra fuel, replace the sensor when it goes bad. Its a job you can do yourself with just a little bit of patience and tool familiarity. Purchase replacement Voyager oxygen sensors from an auto parts store.

Instructions

1

Start the engine on your 1995 Voyager and let it idle until it reaches the normal operating temperature, the temperature your van typically runs at. Locate the oxygen sensor threaded into the exhaust manifold at the bottom of the engine compartment.

2

Unplug the wiring harness connection on the sensor. Remove the sensor from the manifold with a wrench.

3

Insert the new sensor by hand to prevent cross-threading. Torque the sensor to 20 pound-feet, using a torque wrench. Plug the electrical connection in until the connector clicks.

Sophisticated computers that continuously adjust critical engine parameters control almost all modern car and truck engines. The crankshaft sensor is one of the numerous sensors that feed information to the computer.

Function

The crankshaft sensor sends information to the engine computer about the precise position and speed of the crankshaft. Because the crankshaft is attached to the pistons, information about its position allows the computer to determine the relative positions of all critical engine components, including pistons, belts and valves. This makes it possible to time the injection of fuel and the spark plug ignition for optimum performance and fuel economy.

Principle of Action

The crankshaft sensor consists of a metal disk positioned on the crankshaft and a detector that covers a magnetic coil. The metal disks movement past the coil causes a disturbance in the magnetic field, creating a stream of electric pulses that the computer uses to determine the speed and position of the crankshaft. The sensor does not produce direct data about the location and speed of the crankshaft; it sends raw data to the engine computer, which then calculates the desired values.

Malfunction

A malfunctioning crankshaft sensor can cause various disturbances including extended crank time during start-up, rough running, bucking, compromised fuel economy and stalling. If your vehicle is equipped with an on-board diagnostic computer, a malfunction of the crankshaft sensor will trigger an error code to inform you about the problem.

The oxygen sensor in your Buick Regal can fail. It must be replaced right away in order for you vehicle to run properly. The oxygen sensor helps regulate the oxygen and fuel ratio. It senses when more or less oxygen needs to be added to the fuel as it moves through the lines. This controls your gas mileage in your Buick. Its a bit challenging to replace the sensor yourself but can save you money.

Instructions

1

Locate the oxygen sensor on the precatalytic converter. This will be located near the front-right wheel well of your Regal.

2

Unhook the large air-intake pipe that is connected to the air box and rear turbo. Also remove the two smaller air pipes that run from the air box to the blowoff. Now locate the oxygen sensor. You will need to soak it in WD-40 in order to loosen it.

3

Use the 7/8-inch wrench to remove the old oxygen sensor. Locate the stock sensor wire near the engine lift loop. Splice the stock sensor wire and connect it to the new oxygen sensor, using crimp connectors. Apply some of the anti-seize paste onto the threads of the new sensor, being careful not to get it on the sensor itself. This makes it easy to remove next time.

4

Screw on the new sensor as tight as you can by hand. Then use the wrench to fully tighten it. Snap the connector wires back into the wire holders. Reattach the air pipes again.

There are commonly two oxygen sensors in the 4.3 liter engine exhaust system on a Chevy truck. One is the "upstream" sensor located on the drivers side Y-pipe near the manifold and the other "downstream" sensor which is located midway down the passenger side near the catalytic converter. Buying a direct-fit replacement sensor would be strongly advised. Its not much more expensive and it will save you time and effort struggling to rewire the universal after-market sensors.

Instructions

How to Install an Oxygen Sensor in 4.3L Chevy Truck

1

Drive the Chevy truck up onto the car ramps on a level surface and place it in gear or park. Turn off the engine and apply the parking brake. Place a wheel chock behind one of the rear wheels.

2

Grab your tools, put on the safety glasses, and crawl underneath the truck on a creeper if you have one.

3

Locate the sensor you are changing. The front one is located on the drivers side up near the manifold and screwed into the Y-pipe. The rear one is located on the passenger side, down just before the catalytic converter.

4

Follow the oxygen sensor wire to the plug outlet. Unplug the sensor wire from the harness plug. Press in on the clip lock with the screwdriver and separate the plugs.

5

Place the oxygen sensor wire into the slot on the side of the oxygen sensor socket and place the ratchet on the end of the socket. Try to remove the oxygen sensor. If it is stubbornly stuck, remove the socket and ratchet and light the torch. Heat the pipe area around the sensor up, but do not heat the sensor as well. Once the pipe area is good and hot (cherry red) remove the sensor. If you had to use the torch to extract the sensor, allow the pipe area to cool down before proceeding.

6

Screw the new sensor in by hand. You will note that the new sensor has a light coating of anti-seize lubricant on it. Do not wipe this off. It will help for future removal and replacement. Tighten snugly with the ratchet and socket, but do not overtighten the sensor. You do not want to strip the threads of the sensor.

7

Plug the sensor back into the harness plug. Remove the tools and crawl out from under the truck.

8

Remove the wheel chock, release the parking brake, and drive it down off the ramps.

The 2003 Chevrolet Tahoe is equipped with either a 4.8-liter V8 engine or a 5.3-liter V8 engine. With each engine option, there are two oxygen sensors in the exhaust system. Install new oxygen sensors in your Tahoe when you notice a significant decrease in fuel mileage or poor idling. Change the sensors at home to save the cost of a service shop. Buy oxygen sensors from an auto parts retailer or Chevrolet dealership.

Instructions

1

Lift your Tahoe with a jack and position the truck on a set of jack stands so you can comfortably work under it.

2

Locate the oxygen sensor protruding from the exhaust pipe just before or just beyond the catalytic converter. Disconnect the electrical connection from the top of the sensor by pulling the connector apart. Remove the sensor with an oxygen sensor socket and ratchet.

3

Insert the new oxygen sensor by hand to prevent the risk of cross threading. Tighten the sensor with the oxygen sensor socket and ratchet. Torque the sensor to 31 foot-pounds with your torque wrench. Press the electrical connection together.

4

Raise the truck slightly, then remove the jack stands. Lower your truck to the ground.

The Chevy Express van was introduced in 1996, taking over for the older G-Series versions. Like the G-Series, the Express featured three weight classes and several different engine options. While the location of the oxygen sensors on the exhaust systems is fairly standardized, ensuring youre replacing the correct one may require a little diagnostic time. The Express features V-engines, meaning it employs a right and left exhaust manifold. Each manifold is monitored by an upstream sensor. The converter or converters are also monitored by a downstream sensor.

Instructions

1

Put on the safety glasses and start the van up if the engine is cold.

2

Crawl under the van to locate the correct oxygen sensor or sensors to replace. While the engine is running, spray penetrating lubricant along the threads of the oxygen sensor. Keep spraying on and off and allow the engine to run for a couple minutes to warm up the exhaust system.

3

Crawl back out and shut the engine off and then return to the oxygen sensor with the remaining tools.

4

Disconnect the wire harness plug from the oxygen sensor.

5

Place the wire into the slot on the side of the oxygen sensor socket and then place the socket onto the oxygen sensor. Attach the ratchet to the socket and turn the sensor counterclockwise to unscrew it from the exhaust port.

6

Insert the new oxygen sensor into the exhaust port and then thread it in by hand as far as it will go.

7

Tighten the sensor with the socket and ratchet clockwise until its snug. Do not over-tighten or youll strip the threads of the new sensor out.

8

Reconnect the wire harness connection. Remove the tools and old sensor.

Proper maintenance of the oxygen sensors in your 2000 Chrysler Town and Country is crucial to managing the fuel consumption in your van. When the "Check Engine" light is on and your fuel mileage has decreased substantially, buy replacement sensors from an auto parts retailer and change them at home for a significant savings at the gas pump.

Instructions

1

Raise the hood of the van and disconnect the negative battery cable with a socket and ratchet.

2

Lift the front of the van with a jack. Support it on a set of jack stands. Locate both oxygen sensors threaded into the exhaust pipe on either side of the catalytic converter.

3

Pull apart the electrical connection to disconnect it. Remove the sensor with a wrench or a ratchet and oxygen sensor socket.

4

Coat the threads of the new sensor with anti-seize compound. Thread the sensor into the pipe by hand. Push the wiring harness connection together until it clicks.

5

Repeat the process on the second sensor if needed. Remove the jack stands and lower the van to the ground. Connect the negative battery cable with a socket and ratchet.

The Lexus S430 is actually classified as an SC430. The "C" stands for "coupe," which is the only way the S430 model is available. The 430 is related to the 4.3-liter V-8 engine. First manufactured in 2001, the SC430 features four oxygen sensors. Two located up front on the converters bolted to the manifolds (one per engine side), and two more located near the two rear catalytic converters. Although the procedure to replace any of them is the same, the sensors are different forward and aft, and defining which sensor has failed will require a code reader/scan tool and knowing where your number one cylinder is located.

Instructions

1

Determine which oxygen sensor needs to be replaced. Plug a code reader or scan tool into the diagnostic link connector located beneath the drivers side dashboard. Turn the Lexus SC430 ignition to the "accessories" position. Follow the directions of the code reader or scan tool to discover which sensor has failed. Bank one-sensor one is the forward-most (towards the engine) sensor located on the same side as the number one cylinder. Bank one-sensor two is downstream on the same side, near the rear catalytic converter. Respectively, the two sensors for bank two are positioned in the same way on the opposite side of the engine and exhaust.

2

Lift the SC430 if youre replacing one of the number two sensors. The number one sensors may be easier to access from the engine compartment on either side of the engine by the manifold.

3

Follow the wire harness of the sensor youre going to replace until you find the plug. It will be eight or nine inches away from the sensor. Disconnect the plug of the sensor from the plug of the wire harness.

4

Use the oxygen sensor socket and a flex-head ratchet to remove the sensor from the exhaust porthole. A 22 mm wrench can also be used, but the amount of room available may restrict its effectiveness. Turn the sensor counterclockwise from the exhaust porthole to remove. Remove the sensor.

5

Thread the new direct-fit sensor into the exhaust porthole by hand to assure youre not cross-threading it. Snugly tighten the sensor with the socket and ratchet (or the 22 mm wrench). Do not over-tighten the sensor because the threads on the sensor can easily strip.

6

Plug the sensor wire plug back into the wire harness plug.

7

Rescan the PCM using the code reader or scan tool. Follow the directions to erase the code to clear the check engine light.

In 2001, Toyota Camrys were manufactured with multiple engine options. In base form, the Camry came equipped with the 2.2-liter DOHC inline four-cylinder engine which offered buyers excellent fuel economy at a reasonable price. In upgraded form, the Camry came equipped with a more powerful 3.0-liter DOHC V6 that provided more power with slightly increased price tag. The camshafts in each engine are monitored by a camshaft position sensor that records the position of the camshafts in relation to the crankshaft. The positional information is used by the PCM to alter ignition timing and ensure that the engine runs smoothly. A faulty camshaft sensor can cause symptoms such as stalling, sputtering, and lack of power. Checking the resistance on camshaft sensor terminals and comparing that to a specified value is the proper way to determine the whether the camshaft sensor is operating properly.

Instructions

2.2-Liter Engine

1

Open the hood and locate the camshaft position sensor. It is bolted to the lower-right side of the valve cover assembly, on the front side of the engine block. Its a small black sensor with a two-wire connector attached to it.

2

Disconnect the sensors electrical connector by depressing the locking tab on the connector and pulling it away from the sensor.

3

Measure the resistance across the camshaft sensors pin terminals with a digital multimeter.

4

Compare the resistance value on the digital multimeter to the specified value. The specified resistance value for the 2.2-liter engine is 835 to 1,400 Ohms when cold and 1,060 to 1645 Ohms when hot. If the sensors resistance value is outside these parameters then the sensor must be replaced.

3.0-Liter Engine

5

Open the hood and locate both camshaft position sensors; in the V6 engine there are twoone in each cylinder head. The sensor itself is located on the back rear corner of each cylinder head. It is black, just like the sensor for the 2.2-liter engine and has the same two-wire connector attached to it.

6

Disconnect the electrical connectors on each sensor by depressing the locking tab and pulling the sensor connector off of the sensors connector flange.

7

Measure the resistance across each sensors two pin terminals and record that value on a piece of paper.

8

Compare the resistance value against the specified values for the sensors. If the sensor is made by DENSO, the resistance should fall between 835 to 1,400 Ohms when cold and 1,060 to 1645 Ohms when hot. If the sensor is made by Wabash, the resistance should fall between 1,690 to 2,560 Ohms when cold and 2,145 to 3,010 Ohms when hot. The sensor should have a stamping mark on the inside of the plastic connecting flange indicating which company manufactured it. If the sensor falls outside of these specified values then it is faulty.

In 1996, GMC had 26 varieties of eight baseline models, all of which were pickup trucks, vans or SUVs. These models ranged in size from a quarter-ton to 1 ton, and though they had different motors, most of them had two oxygen sensors that screwed into the exhaust system and monitored the ratio of oxygen to burning fuel in the exhaust. The one closest to the motor (on the drivers side exhaust pipe near the manifold) is referred to as the "upstream" oxygen sensor, and the one near the catalytic converter is the "downstream" oxygen sensor. Buy a quality direct-fit after-market oxygen sensor and put it in yourself to save some money on labor charges.

Instructions

1

Drive the GMC onto the car ramps carefully until the front wheels center in the top pits. Turn off the engine, place the GMC in park or gear, and apply the parking brake. Place a wheel chock behind one of the rear tires.

2

Put on the safety glasses and grab all the remaining gear and crawl under the GMC on a creeper. Locate the oxygen sensor youre replacing by following the exhaust system from the front left Y-pipe near the manifold to the catalytic converter.

3

Follow the oxygen-sensor wire to the plug about 8 inches away and separate the plug using the flathead screwdriver to press in on the plastic clip lock.

4

Put the oxygen-sensor socket onto the ratchet and place the oxygen-sensor wire in through the slot of the socket on the side. Remove the oxygen sensor. If the sensor is stubbornly stuck, remove the socket and ratchet and light the hand torch. Heat the area of the exhaust pipe that surrounds the sensor to expand the metal and try again with the ratchet and socket until youre successful. If you had to use the torch, allow the exhaust pipe to cool down before you proceed.

5

Screw the new oxygen sensor into the porthole in the exhaust pipe. Most quality direct-fit sensors should have a light coat of anti-seize lubricant on the threads. Do not wipe that off, as it will make future removal and replacement procedures helpful. Tighten the sensor with the ratchet and socket, but be careful not to overtighten and strip the threads of the new sensor.

6

Reconnect the sensor wires at the plug connection. They will only fit one way.

7

Gather the tools and crawl out from under the GMC. Remove the wheel chock and lower the GMC.

There are two types of water tanks installed on RVs. The gray water tank refers to the holding tank that catches water that runs from your RVs sinks and shower. The black water tank catches waste water that is ejected from your RVs toilet. RVs have tank sensors which monitor the amount of waste water inside your black water storage tank. This sensors let you know when it is time to empty the tank. These sensors do wear out and fail sometimes. If this happens, they should be replaced.

Instructions

1

Drive your RV to a designated waste disposal center and empty out your black water tank.

2

Park your RV on a flat surface and turn on the emergency brake.

3

Locate the sensor attached to your black water tank. It is mounted to the side of the tank.

4

Push in on the two tabs on the side of the old tank sensors electric wiring harness. As you depress these two tabs, pull the sensor wire plug out of the back of the old sensor.

5

Place your wrench over the bolt built onto your old tank sensor. Turn it counter-clockwise, or to the left, to loosen, then remove it.

6

Use an old rag to wipe down the area where your new tank sensor will be installed. Clean off the end of the electric wiring harness by wiping it with the rag. Thread the new sensor into the hold. You can do this by hand to get it started. Slip your wrench over the bolt part of the sensor and turn it to the right to tighten it firmly. Once it is tight, plug the electric wiring harness into the new sensor.