munch

I have a 1999 GT that has SLP LM1'S cat back and I'm looking to replace the rest of the exhaust. I think my converters are clogged because when the car idles and i give it past half throttle it sputters like the air isn't flowing as good as it should.
Was looking at mac pro chamber or an h pipe, I don't really want it to get much louder just looking to get better flow through the system.....any thoughts on my best bet.

TRUEBLUE3934

OK. Saw a bunch of views, but no replies. Nobody else wants to chime in... I will.

LM1's are one of the loudest mufflers on the market. Your cats(or any cats) will quiet the sound level a lot. If you switch to any mid-pipe that has NO cats, you WILL have a loud exhaust. The ProChamber will be slightly quieter than an O/R H-pipe, but not much.

If you want a little more sound, but not incredibly loud, you need to get a mid-pipe with 2 high flow cats in it. That will address the issue where you think you have bad cats, and it will allow slightly better flow and slightly more sound volume.

I STRONGLY caution you about going catless if you don't want to get MUCH louder.

Good luck with whatever you decide to do!

munch

Think i'm just gonna get a couple magna packs or stingers to replace the lm's, will cutting the lm's out and putting another brand in degrade the sound at all?

kast1376

If you dont want much louder, just better flow that what you have currently why not just buy a used replacement stock midpipe? You can find them pretty cheap.

TRUEBLUE3934

If you think you need to replace your factory mid-pipe due to bad cat(s), I suggest getting a high flow catted mid-pipe and see how that sounds first. After that, you can decide if you want different mufflers.

Simply replacing your LM1 with Magnapacks won't degrade your sound. It may chance the tone a bit, but not degrade it.

I'd address the cat issue before changing any other components.

Note: all of the straight thru mufflers combined with O/R mid-pipes will be pretty loud.

jsmarsh25

since you think your cats are plugged up and pretty much screwed, why don't you just poke them out, then you'll get an idea how loud your car will be with an o/r h or x pipe? sounds like they need replaced anyways, so what's to lose?