how much modification is needed [if any] to mount a 00-01 gsr greddy evo2 cat back to a 98 gsr?

 

u'll need to modify the cat to fit. (either shorter or longer) i dont remember which one

 

can i just use the 00-01 cat?

 

The 94-99 gsrs are 2 inches shorter at the header and another 2 inches shorter at the cat, therefore the B pipe is 4 inches longer.

You would need to extend either the catalytic converter, or extend the greddy b pipe.

Either that or you can buy a custom length high flow cat from either Carsound or SMSP.

The greddy b pipe will be 4 inches shorter than the stock b pipe you have now, so the easiest would be to extend the b pipe....BUT watch out, cuz this can decrease the value of the exhaust system because its been *tampered* with.

I say you cut the flange off the cat, and weld a 4 inch pipe with another flange to bolt it up to the *unmolested* greddy b pipe. LIke that you dont lose value on the exhaust because its not modified. The cat can be replaced very easily with many others so i dont see it being a problem.