So i installed an aps tallboy in my 04 g35 coupe. The check engine came on after 2 days. Idle was also rough. So i returned to stock, and still same thing. It is throwing the code p0171 "engine too lean". Now i replaced all vacuum hoses where they belong, cleaned maf sensor, tight seal around manifold... I am totally lost guys.. any help would be great before i take it in to the stealership. thanks

 

I'm having the same problem, if I get it fixed I'll contact you.

 

auto or manual?

 

07 G35S sedan manual

 

Are you modded? You may need a tune to fix your AFR (air/fuel ratio). It could have something to do with your oil as well bad piston ring.

 

No mods. Just staying lean. Could the injectors on bank 1 be the program

 

Problem*

 

Reset your ECU, might fix it