f_l_g

Will an type r cat. fit on my exhaust with a 2.5 in. collector flange? I put some aftermarket tsudo type headers on my car and now the bolt pattern don't match up so i was wondering if the type r cat. will work for this or does anybody have any suggestions for a hi-flow 2.5 inch cat with the secondary oxygen sensor input? Let me know.

Thanks

f_l_g

bump

B18C5-EH2

If you're asking about the difference between a 99-00 Civic Si cat vs. a 97-98/00-01 ITR cat then I'm here to tell you that they bolt up exactly the same.

ITR cats are not 2.5''

f_l_g

ok, well here is my dillemma. I bought a pair of ebay headers but they have a 2.5 inch collector and i want to put a high flow cat on it but i need some opinions on what to get. Not something that is going to drive me broke but something that is going to perform. Where can you get these from?

B18C5-EH2

You might want to look into buying a Magnaflow convertor in 2.5'' at your local muffler shop and have them WELD FLANGES ONTO THE CONVERTOR when they install it so that it can be easily unbolted if it needs to be changed out later down the road. Some shitty shops go lazy and weld them straight in, which ruins your header and exhaust.

You're not going to find a direct-fit convertor since that Ebay header isn't lining up right, because you won't know what car to ask for when ordering it.

Lastly just keep in mind you're opening up an OBD2 Pandora's box by doing these mods - OBD2 computers are already sensitive about throwing "catalyst efficiency low, bank one" check engine codes, so throwing on an aftermarket high flow convertor may be asking for check engine codes for a bad cat convertor down the road - regardless of the name brand convertor you buy.

f_l_g

in that case i think i'm going to buy a new set of headers with 2.25 inch cat.

B18C5-EH2

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by f_l_g &raquo;</TD></TR><TR><TD CLASS="quote">in that case i think i'm going to buy a new set of headers with 2.25 inch cat. </TD></TR></TABLE>

You mean 2.25'' flange on the end where the cat bolts up, right?

If so then honestly if I owned a 99-00 Si I'd do the same. I live in GA where they hook up a scan tool every year in order to pass emissions and get a tag, and an aftermarket 2.5'' cat may or may not keep the CEL off, so IMO the best bet is a buy a nice header that will bolt right up to your stock convertor.

bmoua

since your from CA buy carb headers haha...i just got fined $373 for having a non carb intake...

black_EM1

I couldn't take anymore. HEADER. One bank of cylinders = one header.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by f_l_g &raquo;</TD></TR><TR><TD CLASS="quote">ok, well here is my dillemma. I bought a pair of ebay headers but they have a 2.5 inch collector and i want to put a high flow cat on it but i need some opinions on what to get. Not something that is going to drive me broke but something that is going to perform. Where can you get these from?</TD></TR></TABLE>

eBay, numerous websites. But beware, OBD-2 is picky.