I hope that is false knock....most of the time I get .5-1.5 deg of knock retard...but last night it was jumping all over the place..anywhere from .5-6.5 of retard.Can a knock sensor go bad and just read all crazy?Some times it will just stay at 0.0 on my scanmaster for 10 minutes...then BAM..6.5.I know I have good gas in the car.The car falls flat on its face when this happens...this is driving me nuts..

Also my 02 freaks out and goes lean for a split second...like a flash.Im I running out of fuel?

9.5:1 cr 355ci
7psi of boost
heads, cam

5 gals of 93 and 5 of 100 ....stock intank fuel pump with 106,000 on it and the inline pump from ATI


could my 4" mufflex exhaust hitting the bottom of the car cause this?Im almost sure it hits the bottom of the car when I get into the throttle.

come on fellow boost junkies....help me out

 

I would think that your exhaust would make some issues all the time under load. You said that it is fine for about 10 minutes and then has some knock. I would look elsewhere. Maybe timing could be an issue.