i just had my stock muffler replaced w/ a 18"magnaflow, kept the stock pipe, the muffler guy used adapters as the muffler was 3" in and out. when i get on the gas and let off it does alot of popping like a glasspack, is this normal for a magnaflow or is ther maybe a spot that never got welded and this is causing it.
I am very happy with the mod and the popping is no big deal but was just wondering if that is normal.

Patrick

 

Mine did that for the first week and then stopped. Prolly just breaking the muffler in.

 

It's probably your truck doing a little learning. The reduction in backpressure might have thrown the settings off a tad. Drive it for a couple hundred miles and it should be back to normal.

SL