Unfortunately there is no fixing an O2 sensor. If the "check engine" light is on due to an O2 sensor, it can only be remedied by replacing the bad sensor.
Easiest way is to disconnect the battery cable (negative) for a couple of minutes, then reconnect. This clears the computer. If everything is OK, Check Engine will stay off.
I had all sensors replaced in my 03 Trailblazer and the check engine light stiil comes on. Why?
If it is bad, replacing it will help with the vehicles emissions and put out the check engine light.
Replacing the water pump will not cause the check engine light to come on. Either it is a coincidence or you have accidentally disconnected a wire or damaged a sensor somehow.
The check engine light would illuminate and set a code for the bad O2 sensor.
There is another cause for the code.
Check engine light will come on for various reasons. The o2 sensors could be one of them. If your belt breaks the light will come on and the engine will over heat. I mentioned the o2 sensor because when it comes on for this reason some people have had that light on for years without replacing the sensor.
You should have a check engine light illuminated. If so check the codes.
disconnect the negative battery cable for 30 seconds
Your O2 sensor is a "part that is designed to wear out". there is no standard on replacing them, but if your car is running fine, and your check engine light comes on, and stays on, it's probably an O2 sensor.
THE CHEAP WAY.... DISCONNECT THE BATTERY FOR A MINUTE OR SO. JOSE
If the o2 sensor is bad, replace it. If the sensors are activating the check engine light, then the codes should be checked. The catalytic converter could be blocked or the engine may not be running properly.
If the 1993 Mercury Villager runs rough when the check engine light comes on and the code reader says 34 and 51, there is a problem with an oxygen sensor and the MAP (Manifold Absolute Pressure) sensor. Both parts together will cost around $200.
a fouled out oxygen sensor can result in bad fuel economy, and make that dreaded check engine light come on, it can also make your car "bogg out" / sputter, when accelerating, when replacing, make sure to get the o2 sensor socket, makes for easy replacement... as far as the check engine light you may need to stop by dealership to have it reset, most will reset for free
The oxygen sensor is one of many things that could turn the check engine light on.The oxygen sensor is one of many things that could turn the check engine light on.
Check and fix the engine.
Speed sensor might need replacing. Does the check engine light come on when driving?
Just unplug the negative terminal of the battery for about 10 minutes and that will reset the computer
Most likely there is another issue which may not show up on a PCM code scan. The O2 sensor is reading a lean mixture so, the PCM is giving the engine more fuel. Check for vacuum leaks. The PCM will also richen the mixture to compensate for other problems.
There is not one sensor. All the ECM sensors are tied to the check engine light.
That is what the check engine light is for. It informs you of a failure.
Remove the negative power line to the battery. Wait a few seconds and replace. That will reset the check engine light. darksidesteve
On a 1997 Mercury Mountaineer : The " CHECK ENGINE " warning light is just to the left of the battery voltage gauge
If it is bad the check engine light will come on and set a code for that particular sensor.