This is a 403 afr 230 heads, fast 102, N/W102 T/B, 239/623/113 +2 cam, 04 gto ecm and harness, 4l60e.
its tuned for mass air. month or so ago it started having lean spikes while driving. I couldn't figure it out but I did figure out if I unplugged the mass air it wouldn't lean out, so iv driven it like that the past few weeks. Then I started having problems with a major bogging issue. Ive scanned it and its pulling timing for some reason[only under a load]. If I rev it in park it rev's fine, but know I can foot brake it and its a constant bog timing sometimes going in the negative.
Please help I have an event coming up and I'm lost. Fuel pressure isn't dropping. If U don't see any thing in tune please give suggestions as to what it may be.
I can drive it lite on the gas and it drives fine.