Sunday, March 23, 2014
How Do I Replace an O2 Sensor in a 1998 Chevy Blazer
The 1998 Chevy Blazer has three oxygen (O2) sensors. Two are located up on the front Y-pipe bolted to the V-6 engines manifold. These two sensors detect the fuel-to-air mix in the exhaust and transmit that information to the powertrain control module (PCM). From there, the PCM makes adjustments to achieve the lowest emissions possible while still running properly. The last O2 sensor is located after the catalytic converter. This sensors job is to monitor the efficiency of the catalytic converter.
Instructions
- 1
Apply the parking brake to lock the rear wheels.
2Open the hood to the 1998 Chevy Blazer to allow some light down into the engine compartment. This will be helpful when under the vehicle to replace the front oxygen sensor(s). If you are replacing the rear sensor, opening the hood is not necessary.
3Lift one front side of the Blazer up high enough to rest it on a jack stand and then lift the other side and rest that side on a jack stand.
4Put on the safety glasses and crawl underneath the Blazer to locate the oxygen sensor(s) being replaced. One is located on the left-side Y-pipe up near the manifold connection, the other is on the right-side Y-pipe near the manifold and the rear sensor is located in the catalytic converter pipe just behind the shell of the converter.
5Unlock the wire harness plug from the O2 sensor plug. Use the small screwdriver to press inward and release the lock while pulling the O2 sensor plug and wire away from the wire harness plug.
6Spray penetrating oil around the threaded connection of the O2 sensor where it screws into the O2 sensor port of the exhaust piping. Allow the oil a few minutes to soak in.
7Thread the O2 sensor wire through the closed end of the 22 mm wrench and then place the closed end of the wrench onto the sensors hex-head. Turn the wrench to the left (counterclockwise) to remove it from the port. Remove the sensor.
8Inspect the threads of the replacement sensor. Most will come with a light coating of special anti-seize compound already on the threads. Some O2 sensor manufacturers will provide a small tube inside the box. If applying the compound, be sure to avoid getting the compound on the thimble-tip of the sensor. Only place a small amount on the threads of the sensor.
9Thread the sensor into the port by hand to avoid crossing the threads of the sensor. Tighten the sensor with the wrench after threading the wire through the closed end again. Only tighten the sensor snugly. Over-tightening the sensor risks stripping the threads of the sensor and/or possibly damaging the threads to the sensor port.
10Connect the replacement sensor wire plug to the wire harness plug before crawling out from under the Blazer with the tools and old sensor(s) and lowering the vehicle.
Tuesday, January 28, 2014
How Do I Replace an Oxygen Sensor in a 1985 Chevy S 10 Blazer
The single oxygen sensor on the 1985 Chevy S-10 Blazer is a more primitive design than todays O2 sensors. Its erred to as a non-heated single (one) wired sensor. While it functions similarly to todays sensors, it demands that the engine is up to operating temperature, including the engine coolant, before it begins to monitor the fuel-to-air ratio. Todays sensors have multiple wires with built-in heaters that heat them up quickly to begin monitoring the emissions more readily. This lessens the amount of pollutants allowed into the air while the vehicle is warming up.
Instructions
- 1
Apply the parking brake of the 1985 Chevy S-10 Blazer and then open the hood. Access to the oxygen sensor is on the lower side of the engine, but youll have more adequate lighting with the hood opened.
2Hoist one front quarter of the Blazer up with a jack placed under the frame rail and then lower the jack and Blazer onto a jack stand. Repeat for the other front quarter to elevate the front end completely.
3Put on the safety glasses and crawl underneath the Blazer with the remaining items.
4Follow the front exhaust pipe to where it connects to the manifold on the drivers side to locate the oxygen sensor.
5Follow the wire coming off the end of the oxygen sensor to the wire harness plug mating connection to the oxygen sensor plug. Lift up the release tab of the wire harness plug and then pull the oxygen sensor plug out.
6Put the oxygen sensor socket onto the ratchet and then align the wire of the sensor into the slit on the side of the socket.
7Place the socket fully onto the hex-head of the sensor and then turn the ratchet counterclockwise to remove it from the sensor exhaust port. Remove the sensor.
8Inspect the replacement oxygen sensor threads. If there is no anti-seize compound on the threads, apply a thin coating of electrically conductive anti-seize compound to the threads, being caul not to get the compound on the head of the sensor.
9Hand-thread the replacement sensor into the oxygen sensor exhaust port as far as it will go.
10Tighten the sensor snugly with the ratchet and oxygen sensor socket (placing the sensor wire into the socket slit), but do not over-tighten it. The threads of the sensors are made of much softer metal than the exhaust system to prevent damaging the mating threads of the system. Because of this, its easy to strip the threads of the sensors.
11Connect the sensor wire plug to the mating plug of the wire harness until the lock clicks into place.
12Lower the Blazer and close the hood.