twpetry

iTrader: (1)

Whenever i go WOT my car makes a very annoying popping sound, alot like a backfire i guess. it only does it at WOT. and its not just an annoying sound the car is much slower when this happens. (Almost a full second at the track) At first i though it was the knock sensors, becuz i was getting a SES light, and some KR. Replaced those and that seemed to fix the problem at first, but then it just came back. I have a predator tuner, so i tried messing around with A/F and Spark, and nothing. My brother who was interning at a pontiac dealership said the tech there said that the LS6 manifold i swapped on might not be seating right on the heads, so we loosened that up, and put it back on, that seemed to fix the problem at first, but then it came back. So we decided to stick the old LS1 manifold back on, and wouldn't ya know, that worked for a while and then it came back ..... So now i'm getting very upset, luckily this is happening off track season. but i'd like to get this fixed, cuz driving around i have to be scared of pulling up to cars that would normally be a full second slower than me!

Any thoughts guys? I think now my brother and i have decided new intake manifold gaskets will be our next step. My mods are in my sig. Except for right now i've got my LS1 manifold back on. It seems to me that when we first put the LS6 on it went the longest time before this started happening, then each time we took the manifold off it would stop, but it seemed like it started popping quicker again each time.

Mods: I re-posted this from the Gen III External Section. I just thought it fit both sections and would see more traffic this way.

TransAm11973

did you check to see if your headers are seated properly? If you are getting it only at WOT then I am thinking its a A/F ratio thing.....whens the last time you cleaned you MAF? could be that simple.....but it sounds like you are getting a backfire thats in your intake. What codes are you getting?