Quote Originally Posted by Reptile View Post
It would technically only lean out if he bored the throttle body more, causing the air velocity to be slower across the MAF. A less restrictive intake system up to the throttle body won't necessarily lean him out, because the PCM will make adjustments to the maf frequency from the feed of the air temperature.

That's my theory anyway.
Good to know, so all of this tuning has been a waste of time. I wonder why people dropping pulleys had to add fuel. idiots Time to load my stock tune and wait for the PCM to majically adjust the MAF numbers for me. Heck it takes the guess work out of it all.