Exhaust Gasket reseal?

[duleymane///iS]

Hello, so I took my 1990 318is to a shop yesterday to get a Vibrant resonator installed, the car is extremely loud it is straight piped to a Magnaflow fancy pancy muffler. Anywho the guy says he had to take the exhaust off from where the header connects to the downpipe to weld in the resonator. Now I have a pronounced exhaust leak from where I am more than certain is the junction where the header bolts to the rest of the exhaust system. He re-used the same gaskets, and said over a period of 3-4 days and multiple heat cycles it would reseal. A buddy at my shop said the same thing. Is this the truth or are they both incorrect and I need to replace the gasket? I have to get my vehicle inspected by the end of next month and it is definetly not going to pass. Thanks for your help have a good one.
-Mike

[jeffnhiscars]

I've never heard of a gasket "re-sealing" itself although small coolant leaks sometimes stop from gunk (mineral) buildup at the leak. For exhaust I would use new gaskets since they tend to shred when you take them apart & then theres the safety issue.

For inspection you could try sealing it with muffler cement but that would be temporary if it was mine.

[duleymane///iS]

Okay I am going to order some new ones so I can put them on.

[duleymane///iS]

How many gaskets does it require? there seems to be 2 of them on there

[bastianshaw]

double check all the nuts are tight

[rlotti]

I had this problem too. How many gaskets did you end up using? Have any pictures of them?