came back from downtime super lean, wtf?

[awdsm drft]

Car went down 2 weeks ago when the ecu went out on me. While it was down I installed my giant front mount. Since its been back up the car has been running VERY lean. I thought it was just the auto ecu I had in it but when I switched to a 5spd its still very lean (i know this because the plugs are WHITE). Under full boost at 11lbs it will stutter out like high levels of detonation and it gets worse if I raise boost. It is not fuel cut. I know fuel cut and this is not it. My front mount shouldn't change my a/f should it?
What could cause it too suddenly lean out on me like this?

 

[saxrulez]

what plugs are you running, and what are they gapped at? Are you on racegas(I ask b/c this will cause white plugs)?

 

[awdsm drft]

brand new bpr7es, no I'm not on race gas

 

[SpoOLxExO]

yup, are your plumbing connections tight?

If its "Not fuel cut" its prolly an intercooler hose thats loose/off if you changed nothing else.

Pressure test your intake!!

 

[awdsm drft]

Already leak tested it. Small leaks at the throttle body (which is normal for a 1g).

going to try:
fuel injector cleaner
fuel filter
plug wires
check vacuum lines coming off fpr
o2 sensor
check base fuel pressure

anybody want to narrow my list down?

 

[SpoOLxExO]

all of em look good except for the injector cleaner...

Thats not going to remedy your situation in the quick fasion you're looking for IF it even does anything at all.

Could be fuel filter and wires, thats usually a culprit (on a 1g)

92 GSX's RUUUULE

 

[Wobble]

check fuel filter, you have a fuel pressure gauge by any chance...

I make it a habit to change my fuel filter every 4th oil change... its a bit overkill.. but fuel filters are cheap.. motors are not