Raspy Exhaust (no cats), need advice

[releese78]

A couple months ago, I had the cats taken off and bypass pipes installed, mine is a 98, so it only had one pair.

Inside the car, I think it sounds pretty decent (no drone, barely any louder). I can't say I'm as impressed with how it sounds outside though.

The one thing I was afraid of before doing so was to sound like a ricer, and I think I achieved just that. It sounds like a rattling tin can at mid-high rpm's now.

If I drive very conservatively, the car is pretty quiet outside, the nasty sound only occurs at higher rpm's

I've been doing a lot of reading on here about people who have done the PSE or drilling mods to the muffler (mine is stock, by the way). Anyone have any experience with either of these mods, or something else in conjunction with cat-bypass pipes?

I am not looking for an obnoxiously loud tone, just something a little deeper without the "tin-can" sound.

....I'm sure someone on here will be a smartass and say "Put cats back on dummy!" While I agree, it would fix my raspy, rattling exhaust tone...it's not exactly the response I'm looking for.

Thanks in advance!

[jmatta]

Have you considered high flow cats? My guess is you've actually decreased power because of the lower back pressure. The engine wasn't designed to run without cats. How do you get around the dreaded CEL or do you chose to ignore it?

[Boxtaboy]

I don't think the raspiness will go away by changing your muffler. I have heard a 2000 Boxster S with bypass pipes, and a PSE, and it still had some raspiness even though the 2000 model yr. had a set of pre-cats on the headers. I know you don't want to hear this, but to get rid of the raspy sound, you'll probably have to put the cats back on or get sport cats, and then a throatier exhaust to attain the sound you want.

Or, you can get sport headers, put the cats back on, and you'll also yield a throatier sound without the rasp.

[releese78]

High flow cats may be something to consider. I got around the CEL by using spark plug de-foulers to pull the second set of O2's out of the stream a little, this works great.

It doesn't seem like I lost any power, if not a little more gain at higher rpm's, but slightly less bottom end torque (barely noticeable).

[Dragonwind]

I'm going through the same thing with my 99. I put high flow cats on and it sounds exactly as you described till it gets to full temp, then it isn't as bad. I've pretty much determined that I need to go back to stock but I need a replacement OEM cat first as one had the o2 threads destroied.
Chris

[986rgt]

How many miles on the hi flo cats? I might be willing to trade you. I have factory cats, but would love hi flo ones for my setup.

Steve

[Lobo1186]

I would say if anything its your muffler. or maybe your taste (no offense meant by that of course)

here is a 2.5 no cats with a different muffler. and IMHO it sounds very good.

precision chassis works exhaust cat delete and muffler.