Ever since i installed my header, my exhaust sounds really raspy in the mid RPM's. I dont have a tach or else i'd give you the exact RPMs, but in low RPMs it sounds deep and good, and in the high RPMs theres no rasp at all. On the 99 DX, the cat is right in the exhaust manifold, and replacing the header removes the cat, so you kind of get 2 for the price of one (removed cat + header). Anyway....im getting a catback exhasut soon (header-back?), and when i do, if i welded a cat into my exhaust somewhere, would it remove the raspy sound? And also, would the cat make me lose power? I'm thinking it will, and would a high flow cat make any difference in the sound?

 

You should have a cat no matter what because w/o it you are just polluting the air. Not to mention if it was an exhaust shop that removed your cat, they shouldn't have done that in the first place. Anways a high flow cat isn't going to make you lose power. Just weld it in right after the header. A catback is going to be everything back from the cat, it doesn't include the cat. But if you buy a catback it will come with a resonator in the piping which should reduce the raspiness a lot. I'm sure that the resonator + a new cat will reduce the raspiness A LOT from what it is now. Also it should make it quieter.

 

Your engine needs back preasure so you need a cat, your car will not loose power with a high flow so get one put on. You will love the sound.

 

Yea i know the catback doesnt include a cat, but since i dont have a cat, wouldnt it be a header back? Anyway man, i agree, i do feel bad about polluting the air, i put the header on myself so it wasnt a shop's fault. I've always wondered: does a high-flow cat still pass emissions? And when i put the cat-back on, you guys are saying that a high flow cat would add power because of back pressure? (I'm afraid to ask, I dont want to get another back pressure war going) Makes sense that i need back pressure, but what a cat give me better performance?

 

backpressure is such a myth

 

You don't need backpressure. You aren't going to get better performance by getting a high flow cat, but you will pass emissions and it will probably help with sound and taking out some of the raspiness.

 

i agree with you guys (riceburner700 and devney), a cat back exhaust is designed to have the perfect exhaust size, and so is the DC sports header, so i should just leave them how they are. Once i get the cat back on, i will see how the rasp is, and if it sounds good i will leave it alone because in Michigan i dont think i'll have to take an emissions test.

 

One of the best ways to do it is get the header, cat and catback for an EX instead of DX/LX etc. That way you can use the racing header and catback but you'll have the cat there still.

 

would an EX/SI header and exhaust bolt right onto my block? IDK if im gonna get a new header, but i can always do with some more knowledge. Other than the intake mani/TB and VTEC head, are the y7 and y8 any different as far as bolt-on fitment goes?