ok well ive done a search and cant quite find what im looking for. i have a d16 z6 with mild bolt on mods...i m, throttle body, header, 2.5" exhaust, fpr, and fuel rail. i made the mistake of driving without knowing the fuel pressure and finally got around to buying a gauge. it was about 60psi so i turned it down to stock specs around 47psi (hose removed) and it runs like complete ****....it chokes up like it wants to stall. do you think i now have a bad o2 sensor or am i leaning out?

 

any ideas would help

 

if o2 was bad, cel should come on. pull the plugs. if they're black and sooty (or wet) - you're rich.