[Darksr]

so I had an exhaust leak for some time now and finally had time to look at the car. when I propped the car up, I found out that the previous owner had installed the gasket was burned off halfway so resulting in the nut flying off. but when I looked up the gasket on Acura parts it shows this circular gasket as opposed to the flange gasket installed in the car. so I'm wondering which one I should install or the circular OEM one or just buy another flange gasket.

 

[Litespeed08]

They will both work. The OEM works with the OEM cat but you can also use the one that covers the whole flange (aftermarket). The aftermarket gasket will work better on non-OEM cats like the high flow cats because they use a very flat flange mating surface which doesn't have a recessed or rounded edge in the hole for the OEM gasket to partially sit into.

edit: Some aftermarket cats may have a flange that works with an OEM gasket but not all do. They may work if you tighten sufficiently.

 

[Litespeed08]

Also, the after market gasket is easier to work with and install since it has holes in it that make installing the bolts so much easier while keeping the gasket in place.