So I ordered this header on e-bay of course, and it didn't come with a donut (crush) gasket (of course). Neither did the high-flow cat I ordered. So now my car just farts down the road. The rest of the exhaust is great, but it sounds like garbage because these parts won't seat correctly with each other. Anyone run into this problem before? Any ideas? Thanks.

 

Go to any auto parts store and buy some.

They should be able to match them up.

 

agreed, just tell them what diameter you need they should have it otherwise go to a muffler shop

 

Just an update, but you'd be surprised how many morons out there feel that they can't sell me an "emissions-related" part based on my specs/measurements. I ended up just getting the OEM gasket from NAPA and dremeling out the inner diameter. Fits perfectly.