i have a megan o2 housing which is 2 1/2" and a 3"dp. so obviously there is a problem.
the donut gasket does not but up and make a seal.

is there a gasket out there that will fix my problem? i've checked around and cant
find a extra wide one. i wouldnt care to fix it but it throws off my afr.

 

How do you know there is a leak there? Almost all o2 housings are 2.5" that go into a 3" dp. The OEM donut should seal everything perfectly.

 

depends what kind of DP you have. For example, works dp requires larger donut gasket.

 

i can hear/see/feel it. i've replaced the gasket to awhile back but in vain

 

i have a hks hi power exhaust but i dont know what the dp is, its says nothing on it. it was on the car when i bought it..

 

some crappy ebay downpipes have an issue with the stock donut.