Hey guys, searched for a while and couldnt come up with a straight answer...which seems amazing b/c a ton of you guys had to have experienced this problem too...

i have a 92 Si, it used to have a h23 in it until i swapped it out for a jdm h22. i just bought a new greddy SP cat back exhaust system (from race inspired here on h-t) and basically i guess exhaust systems are not made for non-vtecs. and the story i am hearing is that my cat needs to be modified to work properly. now...everyone seems to know that i have to modify it....but i havent gotten a straight answer on what exactly i have to do.

can anyone shed some light on this for me?

shanks

James

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by volklude &raquo;</TD></TR><TR><TD CLASS="quote">Hey guys, searched for a while and couldnt come up with a straight answer...which seems amazing b/c a ton of you guys had to have experienced this problem too...

i have a 92 Si, it used to have a h23 in it until i swapped it out for a jdm h22. i just bought a new greddy SP cat back exhaust system (from race inspired here on h-t) and basically i guess exhaust systems are not made for non-vtecs. and the story i am hearing is that my cat needs to be modified to work properly. now...everyone seems to know that i have to modify it....but i havent gotten a straight answer on what exactly i have to do.

can anyone shed some light on this for me?

shanks

James</TD></TR></TABLE>

hmm the only thing that makes sense is that the cat needs to be lengthened or shortened?

i don't exactly understand what you mean when you say:
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">i have a 92 Si, it used to have a h23 in it until i swapped it out for a jdm h22. i just bought a new greddy SP cat back exhaust system (from race inspired here on h-t) and basically i guess exhaust systems are not made for non-vtecs</TD></TR></TABLE>

could you clarify?

 

the cats are different between the 4th gen (92-96) vtec and non-vtec models. when i ordered my exhaust everyone is telling me i have to modify my cat b/c i have a non-vtec car and all the exhaust applications are for vtec.

it just seems that everyone knows that non-vtec 4th gens need to do something to their cat to make it work w/ the vtec application....just noone knows exactly what that something is...just trying to find out some info before my exhaust shows up at my door on friday lol

 

I have an obd1 h22 cat for sale if you need it. Let me know

 

Here is what you need to know.

The two differences between 4th Gen VTEC and Si models are the Cat length (VTEC cat is longer) and the cat-backs (VTEC is a little shorter to accomodate the longer cat)

The header downpipe is the SAME length. So, if the catback was available in a VTEC AND Si trim, you should've gotten the Si cat-back.

Now, if you said that your cat-back was only available in a VTEC trim, then yes, you have to either lengthen the cat or extend the cat-back to the cat.

If I were you I would either get a OEM 4th Gen VTEC cat or get a Carsound high flow cat with the flanges modded to VTEC length.

Hope this helps.

 

andyd answering my questions perfectly as always. thanks again man, i think this is the 30th time you have helped me out. lol...i think i am going to just fab. up a testpipe then later down the road pick up a OME vtec cat incase of emissions and such.

thanks again