ok so lately my car has been running very lean. It had thrown a code for bank 2 sensor being lean and the dealer changed the sensor, and when i do data logs it still says im running lean. I had been tuned at 13.2 afr's and now im reading mid 14's to low/mid 15's at WOT... I tried cleaning the maf and no help, i put my stock intake system on, and still runs lean, made sure the plenum bolts were all tq'd to specs and still no fix. I have tried spraying fuel in my intake with a nitrous fuel solenoid with the pill for a 50shot i think it was a f28, and this had my car running with the afr's in the low 11's, is that about where it should be?

I think maybe my maf is going bad, or my injectors are dirty. Tomorrow i plan on swapping mafs with my friends 350z, and making more data logs, and if that doesnt help, im going to seafoam the motor to see if that helps... Any help would be appreciated.

 

what are your mods?

 

a vac leak some where would cause this.... try a smoke test on your intake manifold if you can get access to one.... Do you have a plenum or plenum spacer ?

could be a ton of things but when i had a vac leak on my plenum i just installed i threw this code. i changed my gaskets and re tourqued everything down and i was g2g... no more code..... you can try to clean your MAF with a maf cleaner that wouldnt hurt...

have you dont anything to your motor prior to this happening ?

 

i have already removed most of my mods and now i only have spacer, drop in, and testpipes