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Q: Loud popping noise where header and exhaust meet

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I had an exhaust leak on the left header. Replaced the gasket and fixed it. When I cranked it afterwards, a loud pop was coming from the donut gasket and it would shake the car violently and it happens in random intervals. I don't know if I broke the donut gasket or cracked the header or if it's an exhaust bang. Any ideas on what it could be? Thank you

My car has 68000 miles.
My car has an automatic transmission.

A: Hi there - the "combustion bang" ...

Hi there - the "combustion bang" you hear taking place at the header flange probably indicates a leak at the donut gasket as you suspect. Unburned, or still burning, fuel catches some fresh oxygen at the flange, and ignites, producing the noise you hear. It might help to lean out your carb in the rpm range this occurs - check your plugs for lean/rich clues. It’s also possible your timing is off a tad (not advanced enough).

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