Sputtering in engine bay & out the exhaust

Mileguru · February 21, 2020

Just seeing if anyone has any ideas before I really chase this problem down with data logs, hose connections, exhaust leaks, etc. I'm hearing a sputtering sound in the engine and then out the exhaust (kind of like the chopper sound) when I really get into the throttle. It's definitely gotten worse over the past week.

2017 Sierra 6.2L, Magnuson TVS1900, Alky Control Meth, Magnaflow 12909 muffler, flapper cut out, V4 turned off.

Thanks for any input!

nominion · February 23, 2020

Any chance what you are experiencing is this issue?

Also, have you confirmed that the donut gasket between the manifold and the Y-pipe is in good shape and that the connection is tight? I've read a few things about exhaust leaks due to that gasket. When I dropped my Y-pipe, I ended up bending the gasket upon reinstall and it caused a sound similar to what you describe. Replacing it fixed my self-inflicted issue.

Mileguru · May 9, 2020

My issue turned out to be the gasket for the exhaust manifold. Dealership replaced it under warranty. No more noise and the torque is back to where it used to be.