Stock car 2000, approx 53k miles. The check engine light came on a few days ago.. had the code pulled at the dealership and it was for the oxygen sensor. They recommend replacing it and then reprogramming the computer.

If there's a malfunction with the o2 sensor, shouldn't the car run a little rough? Or are there two o2 sensors and the one that's malfunctioning is just for emissions or something like that? Are there any online places where I can find the o2 sensor cheaper than ~$270? I'm not convinced that it needs to be replaced because the car is still running well, but I'd like to have the part just in case.

 

It's probably the rear sensor and that won't affect performance. There's a TSB about it and the fix is to reflash the ECU with an update. I'd have them do that before replacing the O2 sensor which may not even be bad. BTW, they'll probably charge you about $85 just for pulling the code. Next time go to Autozone and have them do it for free.

 

Ya my check engine light came on about a month ago on my 2000 max w/ 66k. However, I have noticed no decrease in performance.(probably the rear 02)

My question is how easy/hard is it to install an 02 sensor?

I know on my '93 chevy it was easy, but Mr. Max is another story . . .