04 gto lean on startup, then fuel trims get it back to 14.7. I've tried everything in the world, and for some reason, the car goes crazy lean, like 19s to 20.0 on my wideband on startup, then works its way back to 14.7 or so finally after a mintute or so. There is NO in between with it, its either pig rich, then takes the fuel away itself, or lean and then richens up.

One problem is someone else put an MS3 in this car, and "tuned" it. I've had a time trying to fix this sucker and i'm fed up. I've got it good at WOT, but it still has that startup problem. then of course it maxes out LT and ST's one way or the other.

Its got a ported FAST 78, ported TB, and 85mm MAF, MS3 cam, longtubes, etc.