I have a question for ECU fault code diagnosis. Last night I follow the instruction to check the code for the light of "service engine soon" (which is steday on). I found the code and knew the problem is of front right heated oxygen sensor. But the bad thing is that I reset it without doing anything. Today I bring it to the garage to replace the oxygen sensor. But the technician in the garge can not find any problem with engine computer scanning. And he said he can not do anything without the code. So, I got my car back without any repairing.

But now I am worried about the resetting of engine light, is it still working now? If so, where is my previous problem? do I need to something else for my car?

Thanks.

 

The problem may not have come back after you reset it. Wait and see if the CEL comes back on. Then check the code, reset it and tell the mechanic to change the damn thing no matter what the ECU says.

Or you could avoid all this grief and replace it yourself...