2004 Toyota Corolla O2 sensor repalcement


My wife had the check engine light appear on our Corolla. The auto parts guy said it was the “top” O2 sensor. Where is this puppy located on our vehicle? Is it possible to remove it, clean it up and see if that will fix it? Will she do any long term damage if we do not fix it unitl next pay check? Will the cheaper crimp your old plug onto the replacemnt sensor wiring I am finding online be an acceptable repair?

The parts counter guys should really not provide a diagnosis if this is what they did. An O2 code does not necessarily mean the O2 sensor is bad. The “top” sensor is the upstream, or pre-converter, sensor.

What code(s) did the scanner show?

I would not assume the code means “replace sensor.” The sensor can be tested to determine whether or not it’s bad. Don’t throw parts at the problem.

And if the light is off leave things alone.

My wife can’t remember the exact code, nor wrote it down. I could go look it up again when the light reappears.

He specifically stated that the “top” sensor was the culprit. I have no idea where to find this sesor on the vehicle. Is it under the car?

As mc said, do not do anything until you get the light again. Then get the code and post it here. Less chance of wasting money this way.