Hi, my maxima has been showing the service engine light for about 2 months now and when it first turned on it was for code P0135 (which is an oxygen sensor), I changed that sensor TWICE already and the code still wont go off. I have turned off the service engine light many times and no matter what, the code eventually goes back on. So my question is, what would be causing this? Do you think the car needs even a new ECU?

 

Emission codes are crazy....Maybe you have an exhaust leak some where or a clogged cat...I've never heard of someone needing a new ECU because of a persistent CEL !!

 

Yeah I know it sounds crazy but I just had my exhaust system checked out and they said it was good except the muffler (which I just replaced) and the code was still on after, so if anyone has any other ideas please!!

 

check the wiring, especially the plugs. I doubt it'll be an ecu.

did you replace the right o2 sensor? looks loke bank 1 sensor 1; top sensor by the firewall?

 

Yes and ill check the wiring