dc_fan
12-23-2006, 12:50 PM
:help:
The check engine light came on in my wife's van. The code is for an upstream O2 sensor not working properly.
Can anyone tell me where the sensor is & if I change it, how do I clear the code?
Thanks
RickMN
12-23-2006, 06:24 PM
Upstream O2 is in the exhaust before the cat converter. An O2 code does NOT automatically mean that the sensor is bad. It could be an air leak, fuel restriction, etc. If you don't have diagnostic tools, you can replace the sensor as your first choice, but do so knowing that the $50 you spend on the sensor may not solve your problem. As for the check engine light. It will NOT automatically go out right away. The computer will have to complete a "drive cycle" which is X number of starts and engine warmups. If it seems good readings after the drive cycle is complete, then it will turn out the light. But the code will remain in "history" memory for a while longer.
