Originally Posted by
DOHCGS_92
What size is the tip you are running ? and is 2 1/4" your stock size piping ?..
I would go with the advice above, timing lash and leaks, and if thats not it maybe it is the cat. There are alot of things that could contrubute to this. I know in my old LS it would backfire with a stock cat, and 2.5" piping, But I replaced the whole system back to a stock style and it got rid of it, pretty much confirming it was an air flow thing. Does your tip have a silencer ? If so, try pluggin that in and listen for it..
Ohh, when you shift, what rpm range does it do this in, or is it all ranges ?
it's an old oval tip I got years ago which measures 4 3/4" by 3" and it looks like the piping is 2.5"... 2 1/4" is not my stock size piping. I believe it was 2" originally. My tip also doesn't have a silencer. When i shift it usually occurs in the lower rev range....if i'm stuck in slow traffic doing the speed limit or slightly below it will backfire more when compared to high revs. Thanks for the advice man.