I'm ordering my cat back exaust today, and i need to know whether or not i need to buy a new cat too? I read in another thread that its not necessary, but recommended. I read in another thread that by not installing a new cat, the cat back exaust f-ed up the stock cat.

Is there truth to either of these? Can i install my cat back without replacing the cat?

 

You don't need to replace the cat. I've never heard of a cat-back messing up the cat.

 

ok, i thought so.


I just realized I read that on an ebay seller's comments, not a forum. The guys cat going bad probably had nothing to do with the Cat-back, he might have just been looking for a reason to bitch...


...and no, i didnt order my exaust from the same seller

 

You might wanna buy a new cat now if you can afford it because I think the stock cat's diameter and the new cat-back's diameter will probably be differen (stock cat diameter will be smaller). If so, this will defeat the purpose of the new cat-back's 2 1/4" or 2 1/2" diameter and easy air flow.

 

yeah get a high flow cat, they run around 70-80 bucks and will help ur car breathe better than a normal cat

 

I plan on replacing the header in about a month, can it wait till i do that? Most of my money is reserved for loan payments and ****, so i don't want to spend anymore just yet. I was just wondering if i HAD to replace the cat.

 

If you're replacing the header in a month, I would wait and do everything (header, cat, cat-back exhaust) if you can. It'll save you some money and time.

 

I could see time, but how would it save me money? I don't pay for labor as stuff like this me and a buddy do by ourselves. Its not certain that i will be getting the header in a month, it may be a little longer, depends on what other projects i got going. I'm going to call around and see if i can get a good enough price on a cat but if not, it will have to wait.

 

If you got a header and kept the stock cat, and got a cat-back, somehow, you would have to connect the original cat (I'm thinkin 1 1/4" diameter) to the new header and cat-back (either 2 1/4" or 2 1/2" diameter). Now, I don't know how this could be accomplished FREE and without a lot of hassle.
If I were you, I'd wait until you had the money for everything (is 1 or 2 months gonna kill you - probably not), then you can just simply scrap all the old parts and bolt in the new parts.
Oh, and while you're at it......when you get a header, you should also buy a new O2 sensor instead of using the old one. And depending on the header you buy, you may also need an O2 simulator if your header has 2 bungs for the O2 sensors.

 

I'm going to replace the cat when i replace the header. Are you saying that the exaust that i have coming will not mount up to the stock cat?

I realize that its smart to do everything at once. But i throughly enjoy ripping my car apart and putting it back together, thats no issue for me. My only issue is my budget. I have an exaust on the way, i might as well use it. I appreciate you're advice to do it all at once, but that could take untill fall, and by then i'll just have to rip the exaust off for winter anyway. Who knows, well see how the exaust install goes (i may still buy the cat and do that too if i can scrape the cash), but if i can't, we'll just do the exhaust.

...more to come...