I need help because my car is driving me nuts, its a 2003 g35 coupe and I've changed all the o2 sensors and I'm still getting a code for all four of them I just want to get the car smogged and would rather have the issue get fixed than have it get smogged illegally. If anyone can help me it would be greatly appreciated. Also when I take out the battery the readings on the o2 sensors seem to be normal but when I turn it on a second time the check engine turns on and the top o2 sensors mirror the numbers of the bottom ones.

 

^^^
If you did not use OEM ones but purchased cheap shyt from China, that may be your problem?

 

What trouble code exactly.

 

P0031 and p0051 are the top ones but I don't remember the exact code for the bottom ones

 

I have walker o2 sensors on the bottom and I don't remember what brand they are on top

 

Those codes are for the heater in the upstream O2 sensor, they probably died.

 

I'll try swapping the o2 sensor at the bottom to the top and see if that changes anything keep in mind that my g35 has the green pigtails for the upstream