Catalytic converter fitment

[White97RS]

I am looking to upgrade to a magnaflow, etc. hi-flow cat, but the dimensions of the stock converter are very odd (3" in and 2.25" out) does anybody know where I can get an adapter to go from 3" down to 2.25" so that I can put in a universal 3"converter? Any other suggestions?

[FireFighter]

So you want to put a high flow cat on a stock exhaust, WHY? I haven't seen an adapter go from 3'' to 2.25'' in any stores around here, check with an exhaust shop if you are really going to do that.

[White97RS]

stock cat going bad--might as well upgrade--don't want to put all new exhaust on now--not made of money.

[grayman]

Are you sure magnaflow/carsound does not make a univeral 12" oval that is 3x2.25?

the below link is to magnaflow.com 'direct fit' cats page.

suggest emailing them...ask if it is 3x3.25 or if the pic shows a reducer to 2.25x2.25.

http://www.car-sound.com/catalog/dir...spx?PartID=668

[grayman]

If you really want to do this....

universal 3x3 cat.
SLP 3" exhaust conversion kit. (it is a 3" S pipe)
then...you will have plenty of room from POST S pipe to downsize the system into the rest of the stock 2.25 mid pipe. (you could do it yourself with hacksaw, clamps and a trip to muffler shop to get a straight section welded up that reduces from 3" down to 2.25" (the front of reducer section sized to fit INSIDE the new 3" S pipe and the back end sized to fit OVER the stock 2.25" mid pipe, for example. You clamp it all up to see if you like it...or brig the car in and have them do it...or you are halfway to adding a 3" or 2.5 inch full catback seeing as you already have a 3" cat and 3" s pipe.

I dont remember if the SLP 3" conversion kit comes with rear O2 boss...if not you will need to have one welded in the s pipe or get a 3x3 cat that has rear o2 boss already in it.

check out my site for some more exhaust info.

[White97RS]

great info.. thank you..didnt know that was avail. I will check it out

[FireFighter]

Well, atleast you are not gutting/deleting the cat.

[White97RS]

grayman, I went to your website <very informative> as well as SLP's and could not find a part number of the 3" conversion kit. Is it 30045. There is not a good description of it on the SLP site, and their pipe has a flange on it...but mine is welded after the cat. It is also for 93-95 mine is 97. dunno..

[grayman]

the flange is ok. if you get a 3x3 cat the ends will slip over y pipe and over s pipe. Just cut the flange off the end of the s pipe. easy.

get some 3" ubolts until you get things welded. use heavy duty u bolts if you are going to leave it for a while or plan on upgradeing further such as 2.5 or 3 inch cat bac.

94039 (i think) is the number for the magnaflow/carsound cat that comes with rear 02 sensor boss. also, if you have a manual tranny you will need cat with air tube.

you may or may not set of emissions SES code by chinging to 3x3 cat. maybe not as you still have back pressure from the stock 2.25 mid pipe.

[White97RS]

thanks again, gray. Definitely helpful.

[grayman]

np

but learned most all of the 4th gen specific stuff here.

just passing it on.


[img]graemlins/bowdown.gif[/img]

[FirebirdGT]

Originally posted by grayman:
also, if you have a manual tranny you will need cat with air tube.

Why? I have no air tube on my 96 5-speed.

[98Camaro3.8]

I think he's just talking about 3.4s. I believe 93-95 3.4 5-Speeds had the AIR system. Maybe all 3.4s have it?
3.8s obviously don't have it.

[ March 27, 2005, 11:42 PM: Message edited by: 98Camaro3.8 ]