I have a 2017 silverado lt 5.3l with 84000 on it. Upgrades i have done is a volant cold air intake, diablosport predator platinum tune and i put a magnaflow muffler on it and removed the exhaust flapper. I have been getting a backfire/popping in the exhaust. I have checked my fuel trims with my tuner and they do not run that high. I did the reset by removing the ecm fuse and also removing the battery cables i do smell a little exhaust once in awhile. Could i possibly have an exhaust leak at one of the flanges causing it. I am only hearing the backfire/popping underneath the vehicle. The vehicle does with and without the tune on it.

 

Popping coming from the exhaust is usually caused by one of the following:

1) a misfire
2) a rich fuel mixture leading to a condition called over-run, where a hot exhaust manifold ignited unburnt fuel. Over-run can also be caused by weak spark, not fully burning the a/f mixture.

 

Welcome to the forum. Moving your post to the Silverado section where it will get more views as this is just the Welcome New Members section.

 

My oiled cold air intake filter caused my maf sensor to malfunction causing the backfire. I did new plugs and wires in september and did not really check the plugs but one of them had a hairline crack in the porcelain and caused it to break part of it off which caused the misfire.