I installed IHE on my car just over a week ago and since I've had it, whenever I let off the gas when shifting, or just slowing down, I sometimes hear 1 or several popping sounds coming from the exhaust. I'm hoping this is just from valve overlap (like the insane crackling sounds rally cars make with the flames on the tail pipes) but I want to know that this is normal, and isn't harming my engine.

 

I always thought it was exhaust reversion coming from the valves...

 

this is normal though?

 

Are you running a cat converter? It sounds like you are running rich enough to have a little extra gas exit into your exhaust and burn off. Nothing to worry about unless you have to pass emissions tests. Running too rich also inhibits performance, but it depends on your overall setup.

Note: This, in more extreme cases, will produce flames from your tailpipe.

 

I have a cat, yes.

will this harm my exhaust system?

 

It may clog the cat sooner then it normally would, but it will not hurt the actual exhaust.

 

ah well. it sounds awesome. I don't mind if i have to replace the cat sooner

 

your just back firing, nothings wrong at all. by installing the ihe your a/f ratio changed a bit which causes you to backfire when down shifting or slowing down. my car does the exact same thing. nothings wrong plus it sounds cool haha

 

ya its just a back fire my car does it too. i sounds like a bubble bursting inside my exhaust and thats all it is basically. i love the sound though.