5zigen headers connecting to stock cat

[jks24]

I installed 5zigen 4-2-1 headers on my em1 today, problem is the outlet for the headers is to wide for the stock cat and its needs to be about another 10mm longer. My question is will i be able to buy a cat that can connect to the headers on one side and still connect to the stock exhaust pipe on the other side which is a smaller hole?

I need to know and get a cat asap as I cannot drive the car atm

Thanks :)

[mnc]

Your best bet is to buy any aftermarket cat and get flanges suited to fit the headers and exhaust.

or

You can buy any jdm equivalent cat and then buy any jdm exhaust system,
I know it will cost more but it will save you some bux in the long run if you plan to ever get a new exhaust system afterwards.

all the best.

[jks24]

Your best bet is to buy any aftermarket cat and get flanges suited to fit the headers and exhaust.

or

You can buy any jdm equivalent cat and then buy any jdm exhaust system,
I know it will cost more but it will save you some bux in the long run if you plan to ever get a new exhaust system afterwards.

all the best.

ok so you can get cats that are say 2.5 inch on one side and 2 inch on the other? I wasnt planning on getting an exhaust yet so I would prefer not to unless I absolutely have to
also do i need to get a new gasket?

thanks