I got under my car pretty much for the first time yesterday when I took the manifold off to put my header on while doin the mini-me swap, and noticed that there's no cat. I can get an inspection sticker w/o it no prob, but would a hi flow cat be better? Whoever had the car had the cat taken out... with 2.5" pipe ran from the downpipe to the muffler... which is probably overkill for the 1.5 cx. And the funny part is... that the stock downpipe is what... 1.75" or something like that (it looks tiny as hell) and it goes to a 2.5". Just odd... but it was a girl that owned it... lol (no offense)

 

if you don't have a cat and it sounds good and you can get a inspection sticker then don't worry about a cat, unless you care about the enviroment (which is a good thing if you do)

 

You might wanna edit that girl part. "(no offense)" doesn't somehow not make it sexist.

Imo, decatted exhaust smells terrible, and I wouldn't selfishly make other drivers on the road smell it to gain a few hp, if that. And just as important (imo) would be the negative environmental effects. It seems selfish to me in this regaurd as well. Who doesn't want more power out of their cars? Why should you get to run a test pipe while the rest of us are doing what we're supposed to do to help the environment? You may disagree, but these are just my views on the matter. I'll always be catted (high flow catted, that is). The only areas I would condone decatting are in real motorsports, and not even in all of those.

I have a pretty adverse view on it, eh?

 

Right now i am running with out a cat just because my old one we had to cut the bolts off when we put the magnaflow catback exhaust on and the funny thing is it came with a straight pipe that could replace the cat, so we did because we didn't fill like drilling out the bolts in the cat. Soon i will get a magnaflow cat so it will match my magnaflow catback exhaust.

 

I hate it when people run gutted cats or even no cats at all... its just loud and nasty sounding, not no mention illegal. Is your car turbo'd? you keep referring to a down pipe and a decent aftermarket downpipe is larger than 1.75". if you want the max potential out of your exhaust system then go with a 2"-2.25" (2.5" should be alright also) from the header back to the muffler and have them install a magnaflow hi-flow cat (cost about $60)

also with the different diameters in piping you have: its like a highway with a lane closed for part of your drive. And you know how slow and annoying it is to drive the highway with just one lane

 

I currently dont have a cat and working on getting one (DX, LX issue) and I will say I have recieved very noticable gains. BUT, the problem is my backpressure went out the window so the torque licks *****. I dont feel power at all until I hit 3 rpm. Adding a high flow cat will not only add more torque with backpressure, it will also stop the notion that you are smuggling chainsaw engines.

 

Ok... I didn't take the cat off, it was like that when I bought the car. And as for the downpipe, It's the stock manifold that I am talking about, which she had run straight into the 2.5" pipe that ran straight to the muffler. I just got my header bolted up, I'll take some pics tonight when everything gets put back together and post up tomorrow... No my car isn't turbo'd, i could only wish... I just thought that the 2.5" pipe from the stock downpipe back was a little overkill since she didnt have anything done to the engine on a stock cx. But anyways... hopefully that cleared things up a bit, sorry 4 the confusion.

 

??

 

^ what dont you understand?

 

The part where "backpressure" does anything. According to the sticky in this section, backpressure does nothing but retard power.