Hello Everyone,

I have a 2004 G35 Coupe automatic. I recently installed new Stillen Cold air intake and a plenum spacer. After 60 miles of driving the check engine light came on. I am showing codes:
P1148
P1168
P1031
P1051

Any suggestions and what could be the problem? Car feels like is running better but when I start it does not feel like before the upgrades. I had not check engine light prior to install.



Thanks

 

I suspect your scanner is misinterpreting the codes, none of those are legit DTCs for the 2004 coupe.

I suspect you have a large vacuum leak though since those are generic O2 sensor and closed loop codes.

Did you do an ECM reset and Idle Air recalibration?

 

Thanks for your reply. I did not do a ECM reset and Idle Air re-calibration. I will try that today.

 

https://nicoclub.com/archives/g35-35...procedure.html

Double check to make sure you didn't accidentally pinch the oil fill neck between the two plenums. Also double check to make sure the intake pipe and PCV hose are on airtight.