Well after swapping the pcm and the knock module I hooked a fuel test kit to it and measured the psi at 40 key on, ideling, and steady rev. with the fpr vacuum disconnected it was about 50 psi. But while I was under the hood I was hearing a noticeable whisteling but I sprayed wd 40 every where that I could see and no difference in engine sound. But I do think it is a vacuum leak cuz when I hold the throttle open steady and increase lightly it gets louder to a point then stops, when I let off it comes back but like I said I'm having trouble pinpointing it. So a vacuum leak would explain why my fuel trims are all off, severe knock retard, bad mpgs. It seems to be somewhere around the back of engine or around the crossover pipe. When I twitch the throttle it also seems to hang for a second just above idle speed.
Thoughts?
