Hello every one , i just became a member and first time owning an Infiniti i have an 07 G35 Sedan Journey is been giving me couple issues, first a service engine light came up for an oxygen sensor bank 1 sensor 1, so i took it to a mechanic and got it replaced, same light came up again a month later took it back they told me it was my fuel sensor so they replaced it, light came on again they said it was my Y pipe that was rusted and had some holes and that was triggering the sensor, and now they are saying is my mass air flow sesor!! Any help please i feel like im just waisting my money the code it reads is (P2A00 O2 Sensor Circuit Range/Performance Bank 1 Sensor 1) i would really appreciate any suggestions any help any recommendations

 

First thing I would suspect is a vacuum leak, that code basically just means that bank1 is lean for a specified duration. Lots of reasons for running lean but your downstream exhaust past the cats isn't going to cause it.

MAF can be cleaned with spray MAF cleaner.

Smoke test the intakes.

I would also get a new mechanic that actually troubleshoots and doesn't just throw parts at the car, what's the LTFT and STFT on bank 1, watch the realtime data, overlay the O2 sensor data, overlay the injector duty cycle, find out why it's doing what it's doing.

Don't be afraid to take it in to Infiniti/Nissan for a 1 hour diagnostic, Consult-III tool can do a lot of things that a handheld scanner can't.