what kind of high flow cat do you run?

im going to replace both my old cats with a high flow..i found one on ebay http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&rd=1&item=2474893475&category=33629 good? bad? or does anyone have a suggestion on what to get for the best bang for the buck..thanks

well

depending on if u have to pass emissions or not i would just gut the cat that u have. i have found that to be better than any high flow cat lol. but if u have to pass emissions u gotta have one.

well i would like to pass emissions, and be able to have this local shop legally do the work i want to it..so i would like to have one cat, and it be a high flow...is the stock pipe on our cars 2.25 or 2.5? the one i got up on ebay right now is 2.25

oh ok

i believe its 2.25 but i could be wrong someone else should chime in here in a minute

I thought the stock 2.3 Mustang exhaust was 2", but I could be wrong.

well i guess i'll just have to go on out and just try and measure the pipe, it'll be kinda hard since its cut at an angle..i need to find out so i can ditch those cats and get a high flow in there..i can imagine i will notice an increase in some sound maybe? along with a little gained power..im not expecting some awesome balls to the wall power or anything, but when give it some gas after 2nd gear it kinda bogs down a bit then builds up

Random question: what about using a cat from a larger vehicle, say one with a stock 3 inch pipe, or at least something from an older V8, like a 351 single pipe exhaust? In theory, if a 351 V8 can flow well through a cat like that, then a 140 I4 ought to be able to flow even better, no? On the other hand, how well would that cat be at actually getting emissions passed, or is a cat a cat?

Gutted mine last weekend and car ran better ever since. But i'm not worried about emissions

I think the ebay cat your looking at is fine. You'll be legal, and you'll be losing your other cat. All hi-flows have the same honey comb catalyst(that I know of, someone tell me if I'm wrong)that looks like a grid. If the cats diameter is wrong the shop you go to should be able to use a pair of reducers to make it fit. If you want to have near zero restriction get an exhaust cutout from Summit then get a McCord power plate(it is a motorized butterfly valve you can open and shut from the cockpit) and mount it ahead of the cat. I'm going to try to do this this summer, we don't have emmissions here in Virginia.

i think im going to get one of them off of ebay, i dont think i can really go wrong with it

Don't buy that crap. I have Carsound Magnaflow cat.

Emmissions if that is the case then go with the high flow but if you can dodge the testing or you dont have it all together then just cut the cats out and gut them both weld them back in and flow better that you have before and get your hp back.

3" straight pipe.

i have a section I swap out around smog time. Its from the header to the end of the cat with flanges. One is straight thru, the other one has a catco high flow cat on it... the catco supposedly works pretty well compared to stock... no numbers to report but that's what im told.

Just incase anyone cares, heres a pic of whats inside the cataylic converter



I gutted mine because the inside looked like this



I put a step by step on how to gut one if anyone cares. goto

http://forums.stangnet.com/showthread.php?t=456822

Anyways pictures are always fun

I replaced my clogged-and-leaking stock cat with a Catco high-flow model, and, while it ran better, I didn't notice any performance gains.