Hello peoples need some advice on which exhaust gaskets i have to use on both ends of a genuine cat pipe on a mongoose exhaust system. The manifold and downpipe is standard but the decat, mid pipe and backbox is all mongoose. After the decat is a short collector pipe i think thats what its called. Basically im putting the original cat back on for mot as its been been parked up for 2 years and its coming back on the road and ive had it since 2003. Do i have to buy two dougnut gaskets, one three bolt triangular and a 2 bolt oval type gaskets? Im honda braindead as ive been stuck in a new ford galaxy for family use, good for economy and comfort but i just miss my MB6's VTEC THRILL. Appreciate some advice please?