Well I pulled the code p0138 or 0510 and ive been researching for about an hour. Most of the stuff I've found is, of course from the 5th gen forums, i guess it's extremely common on them. Well I know where the oxygen sensor is and exactly how to replace it, but the code is a maximum voltage code not a circuit fault and idk if that means the o2 sensor is bad. This code means the car is running rich that could be from any combination of things but I don't know what.

My question is of all the solutions I've found on the internet and the org the most common has been i reset the ECU and it never came back is it that simple? Can I just replace it? I had some exhaust work done the other day could my cat be bad?

 

http://forums.maxima.org/showthread.php?t=401089

 

haha now i feel dumb

Side question people always say universal o2 sensors are bad but I fix electronics for a living so im sure i could make a good connection with the harness and the o2 sensor, is there any other reason they aren't as good besides getting a good connection.

 

Well, the thing is you approached it in a very good way. Yes, if a sensor is dead it will throw a semi different code. But in this case you though, the sensor is not the root cause of the problem. Good thinking anyhow