Exhaust

When I rev the rpms real high then let off the exhaust pops real loud. Only when im not on the gas though.Any Ideas? Plus I have no exhaust leaks. !!

Are you sure you dont have an exhaust leak? Sounds to be the problem to me.

When I rev the rpms real high then let off the exhaust pops real loud. Only when im not on the gas though.Any Ideas? Plus I have no exhaust leaks. !!

its probably just from running rich, my friends wrx pops and backfires all the time from running rich

Yep, either running rich or lack of a cat will do that. My exhaust sounds like crap when idling and revving it, but when I go WOT it sounds awesome, especially in LONG tunnels.:D

So if you were to fix that exhaust leak, the popping would stop?

Hmm... because I am looking to buy a friends '91 SL and it has some sort of dual-muffler system... one pipe, but there is a leak in the flex-piping by the main cat though. And it sounds like a muscle car when it idles and your at low RPM. But if you take it up to like 6k and shift, it pops. So if I fix that whole flex-piping thing, it would solve that problem?

i can be many things but the most likely is either lac of restriction in the exhaust, rich fuel mixture or leak in the exhaust. you dont see it all the time it can be in the manifolds as well. or a burnt gasket for the manifolds

I had the same probalem with my old stock exhuast, It sounded just like a muscel car and poped. Then i bought borla cat back for it with a high flow cat, and it went away.