does any1 know if you need to remove the OEM cat converter or modify it 2 install this? or does it fit wit no modifications on a GSR b-series?? please help, im planning on buying this header and want 2 know if i shud expect any surprises or changes

 

most of the time, you usually only have to get your cat converter modified to fit the header. but why would you want to put headers then go to a stock cat. get a hi-flow you'll be happy.

 

Depends on the header. If its made to bolt to the stock cat, it will fit....if its the "race" or "JDM" version, then it will not because of the larger 2.5" collector.

 

if your talking about the hytech replica tri-y then you have a few options but they all require modification of the exhaust because it deletes the stock cat conv.

#1- the exit flange is 2.5" so it will not bolt to the factory cat anyway
#2- you can make i custom test pipe to make up the distance between the header exit flange and start of the b-pipe.(this is the option i chose, the distance is almost exactly 5 1/2")
#3- you can cut the b-pipe and add a high flow cat if you have to pass smog. remember the flange must be 2.5".

hope that helps, but unless you can get a cat that is 5 1/2 inches long there will be some modification needed to make it fit.