Ever since I put the Magnaflow cat back on I get a popping sound from the exhaust inbetween shifts. Its not a good pop like borla I know pops like mad. This sounds like a misfire out the tailpipes. I have searched through the site and not found much of an answer. Any help would be great.

 

maybe you need a tuneup? your stock mufflers could have been masking the pops before.

 

I forgot to mention I have a brand new water pump, GM opti, GM wires & plugs! I keep meaning to do the fuel filter. But I dont think thats causing a backfire. What else?

 

Check egr system, one of my vaccuum lines came off and caused popping. Also check the evap lines evap lines . I broke one of these and did a half *** job on the fix. About 2 weeks later the vaccuum line broke again causing louder popping

 

go over you spark plugs where they snap onto the plug and opti..

 

your car might just be running rich.

People have had the same problem, and once they had the engine leaned out a little bit. It got rid of most of the popping and backfiring.

Im not sure if this is the same issue. But LT1's do run rich from the factory.