got a b16a2 civic si with bolt ons, cams, port and polish. im getting itr headers (2.5) with a 2.25 obx high flow cat, and a greddy sp2 (2.36 piping). question is, would this be a good set up having the 2.5 inlet/outlet header and the 2.25 cat? thanks

 

my opinion is no cause cause basically u going from a great headers to not so great cat. All that power that u might have gain by changing the headers gets stuck at the cats if i would u i would take the cat out and have a 2.5 pipe all the way back. The drawback in that is that u wont have a can and might not be able to pass emissions but if u live in a place that they dont test for emissions it does not matter. Now there is another thing if u got straing out 2.5 piping all the way back is that ur going to have a check engine on the only way u can not have that is go with a obd2b jumper harness to obd1 and get a p72 or p28 and get it chip for ur set up and doing that will take ur govener out and u can adjust the time the vtec hits so more power.

 

sure why not.... why would there be a problem with that?

 

keep your set up, it's legal and better on the enviroment.

 

i dont really think its a problem cuz i have a 3 in down pipe for my turbo and 2 3/4 after that all the way to the axle back....dont really see why it wont work but it sure did for my turbo setup...

 

legal by putting on a bigger header and doing modifications on a car u no longer fall in legal stats unless is complete bone stock which i seen but only for a day after that is so elegal that we pay to make it pass

 

what does that even mean?

headers are not illeagal.

 

keep that set up? so it would be good?

 

as long as everything bolts up, which I assume it will, the small difference in size wont effect it much.

 

did anyone else understand this?
i sure didn't...



OP: it's fine.

and no, don't take out the cat, that is retarded. anyone who runs without a cat... i hope they die of carbon monoxide poisoning.