I just installed the dc sport downpipe and it seems the donut gasket doesnt fit all the way around the pipe. From the 02 housing to the downpipe flange there is a small about half inch gap where the donut gasket is filling this gap. Is this how it is suppose to fit?

 

ttt

 

my megan racing dp came iwth a donut gasket that was apparently too big, i just used the factory one

 

if it doesn't leak, it should be ok. However, 1/2 inch seems bit too much gap.

 

You are supposed to use the megan gasket. No gaps should exist for megan. It is not the dount type. megan has the flex section instead.