exhaust system is Header->downpipe->Cat->pipe->muffler (if you take out the resonator, like I did)
catback is a word used to describe the setup, it's not a part.

my piping is stock, and IIRC it's 2 1/8" ID. 3" would be too much for a NA setup on the 2.4. would be perfect on boosted though.

if the only thing you're doing is the header, you should be good doing just the front. Get it as high as you can without putting the stands on the suspension though. firm on the "frame"

The exhaust system is typically the manifold/header, down pipe, flex pipe, cat, resonator, muffler, and the piping connecting them all. I have a header into 2.5" mandrel bent and I wouldn't go any bigger for NA.

Also, when you connect the header back to the head there is a specific torque sequence that you are suppose to follow. Starting in the center and working out at a certain value then do it again to a higher setting. This prevents warping of the head. The connection really does not need to be uber tight either, that is what the gasket is for.

^ Thanks! I didn't know that, but I figured it was common sense. lol I treated it like the lugnuts, "trying" to do the star pattern.

i have the ecotec. seems most recommend about a 2.5" piping. already got a header and a muffler. does getting a highflow cat really help?

if you already have the muffler and header installed, don't bother. if you don't have them installed already, sure go for it. the stock Cat flows fairly nicely, if it's in good condition.

Just by luck, I purchased a high-flow cat online. days later (before the high flow arrived) the stock one clogged and burnt up...so I needed to replace it anyway.

ive been thinking about replacing the cat while i was under there, seeing as the original one has 165+k on it, but there doesnt seem to be any issues with it, and im quite tight on money, so ill probly leave whats there, especially since i may not be able to weld it all up. really looking forward to getting the header on tho...

when there are no problems, I've heard that factory cats can last up to around 400k. I wouldn't replace it unless there's a problem. If you do, keep the old one...maybe you can sell it. hehe

it would end up taking more time and money than i really want to spend to replace the cat too, so its just the header for now.

curious to know what the symptoms are that would indicate a bad converter? It's not an issue that I have ever encountered. Just curious... :)

well, depends on how bad it is. if its absolutely clogged, exhaust pressure could build up and eventually cause misfiring. if its just not converting well, the sensor will pick it up and shoot you a dummy light.

cool. Thanks for the info! :)

suprised i havent had any issues with mine. cars been lowered for about 8 months, and the cat seems to be the lowest part of the exhaust, thus hitting on speedbumps, and steep inclines, but havent got any codes or change in performance.

no sense starting another thread with the same topic, so ill ask here: did anybody who installed the header wrap it first? i ask because my brother just wrapped the headers for his 87 grand prix, and has some left over. just wondering what peoples thoughts were. he told me it voided any warranty on the headers tho, but what can really go wrong besides some rust?

wrap stops more heat from emitting off the header and supposedly forces the heat to move father down the exhaust b4 it escapes. and commercials say that happening would give you more power, but i highly doubt it.

as long as the air coming out of the engine isn't obstructed, it doesn't matter how hot it is. The stock heat shield is on there to protect the gas tank from the heat from the exhaust.

ill probly do it anyway since the stuff is so inexpensive. cant hurt right?

unnecessary added weight...plus if you get moisture in there, it makes the pipes more susceptible to rust. more cons than pros. better off just going without it.

i dont think its gonna make any difference with the weight of it, its just fiberglass cloth. and there is a silicone based spray that you put on after wrapping them to prevent moisture. but i know when my brother did it he was covered in fiberglass fibers, and he had a hell of a time doing it. havent decided yet tho. if i get the header before my next paycheck, im just gonna put it in w/o wrap. if i get more money before the header, i may wrap it before installing.

Wear rubber gloves :yahoo: