I need an exhaust!!

[knate20]

I have a 99 grand prix se. and i need the whole catback system. i was wondering if anyone could help me out findin one cheaper than 600 bucks and would sound good also!!

[Durk Diggler]

Do you have a 3.1 or 3.8?
Either way just doing a catback is going to make the car slower and annoying loud.

[JGT010]

How does a Cat Back make a car slower.

[knate20]

its a 3.1. basically i need everything from the headers back.

[blueguy]

How does a Cat Back make a car slower.

For one...since it is a 3.1 V6 it isn't going to do squat...even a slew of mods won't make that car any faster. And anything powered by a 3800 have actually been proven to LOSE power when not making over 350+whp. That is because the stock catback flows THAT good.

its a 3.1. basically i need everything from the headers back.

Manifolds. They don't have headers. And, no one makes headers for the 3.1 V6. Are you wanting a performance gain? Then go to Milzy Motorsports, buy his ported manifolds, larger downpipe, and go to an exhaust shop and have the catback custom done. Just leave in the resonator for god's sake. You can take out the car but leave the res. And after you do that you might as well open up the intake side of it with a cold air intake...then a Tuned PCM and colder T-Stat...get new spark plugs and wires too...just remember the 3.1 V6 is no powerhouse. I'd save for a 3800 to swap in or keep it running good and trade it in for a 3800 or 3800 Supercharged car

[JGT010]

Well I am having a Performance shop install a SLP Cat Back on my 07 Grand Prix GT Friday. I purchased it from SLP and they drop shipped it to the shop. The guy at the shop said it would open up my exhaust and i would pick up about 10 HP or so. He even mentioned it was possible to gain a few MPG. Now one thing I've been told the OEM mufflers aren't that restricting but the pipe is. Factory pipes have some minor crimps in them and they are not stainless. Most of us here use mods like CAI, FWI, Pulleys, Headers and Cat Backs, and of course PCM tuning. All these mods add some Horse power to the wheels, crank whatever. I've been hearing some horrors stories from mechanics about PCM tuning though. The PCM can support some changes from mods like CAI, Exhaust changes, T-stat, colder plugs and even the SC pulley as long as you don't try to run one the size of a quarter. I like having a good running car and some of these mods are nice and they do add some power. But the only way you truly make a car fast is to go into the engine and transmission not the PCM or the exhaust or change T-stat and spark plugs. Those are minimal changes that your PCM can deal with. Ya want 500 HP at the wheels do all those simple mods if ya want then find a real sharp cat that can get into your engine and tranny. I've heard some guys say on here they've blown engines because of so and so's PCM tuning. I would honestly say that the popular online PCM guys and I don't have to mention who they are do I. Probably spend 15-30 min with your PCM and then ship it back to ya and the ones off the shelf, don't expect much out of those either. Find someone local who has the equipment and knows your vehicle and let him spend a few hours refining your PCM's parameters. I think all mods have some value in terms of adding power to a car but be cautious how far you go. I don't race my car, I'm willing to bet most of you don't either ya just want a street beast, nothing wrong with that really but make it a stable one. I can go on and on with this but I think ya all get it.

[Durk Diggler]

My Monte had the 3.1 it is crap. Set some money aside when the LIM gaskets die. It is a crap job I will never own another GM vehicle with the 60* V6.
There is a 3.1 "topswap" in which you take the upper and lower intake manifolds and throttle body off of a newer 3100 motor. I don't know much more about it than that. The loss of back pressure in an even smaller V6 engine will make it slower. And the 3.1s sound terrible with open exhausts, go to youtube and a quick search will yield some pretty hilarious examples.
JGTO, I'm sure you can appreciate the difference between these two comments.
I need a catback for a 3.1.
I'm getting a SLP performance catback for my Gt.

[blueguy]

Well I am having a Performance shop install a SLP Cat Back on my 07 Grand Prix GT Friday. I purchased it from SLP and they drop shipped it to the shop. The guy at the shop said it would open up my exhaust and i would pick up about 10 HP or so. He even mentioned it was possible to gain a few MPG. Now one thing I've been told the OEM mufflers aren't that restricting but the pipe is. Factory pipes have some minor crimps in them and they are not stainless. Most of us here use mods like CAI, FWI, Pulleys, Headers and Cat Backs, and of course PCM tuning. All these mods add some Horse power to the wheels, crank whatever. I've been hearing some horrors stories from mechanics about PCM tuning though. The PCM can support some changes from mods like CAI, Exhaust changes, T-stat, colder plugs and even the SC pulley as long as you don't try to run one the size of a quarter. I like having a good running car and some of these mods are nice and they do add some power. But the only way you truly make a car fast is to go into the engine and transmission not the PCM or the exhaust or change T-stat and spark plugs. Those are minimal changes that your PCM can deal with. Ya want 500 HP at the wheels do all those simple mods if ya want then find a real sharp cat that can get into your engine and tranny. I've heard some guys say on here they've blown engines because of so and so's PCM tuning. I would honestly say that the popular online PCM guys and I don't have to mention who they are do I. Probably spend 15-30 min with your PCM and then ship it back to ya and the ones off the shelf, don't expect much out of those either. Find someone local who has the equipment and knows your vehicle and let him spend a few hours refining your PCM's parameters. I think all mods have some value in terms of adding power to a car but be cautious how far you go. I don't race my car, I'm willing to bet most of you don't either ya just want a street beast, nothing wrong with that really but make it a stable one. I can go on and on with this but I think ya all get it.

What did you say? I didn't want to read the rambling. The stock catback is proven to flow efficiently up to 350+FWHP...it isn't restrictive at all. And saying you gain 10hp from a SLP catback is funny.

[silverstreak]

Well I am having a Performance shop install a SLP Cat Back on my 07 Grand Prix GT Friday. I purchased it from SLP and they drop shipped it to the shop. The guy at the shop said it would open up my exhaust and i would pick up about 10 HP or so. He even mentioned it was possible to gain a few MPG. Now one thing I've been told the OEM mufflers aren't that restricting but the pipe is. Factory pipes have some minor crimps in them and they are not stainless. Most of us here use mods like CAI, FWI, Pulleys, Headers and Cat Backs, and of course PCM tuning. All these mods add some Horse power to the wheels, crank whatever. I've been hearing some horrors stories from mechanics about PCM tuning though. The PCM can support some changes from mods like CAI, Exhaust changes, T-stat, colder plugs and even the SC pulley as long as you don't try to run one the size of a quarter. I like having a good running car and some of these mods are nice and they do add some power. But the only way you truly make a car fast is to go into the engine and transmission not the PCM or the exhaust or change T-stat and spark plugs. Those are minimal changes that your PCM can deal with. Ya want 500 HP at the wheels do all those simple mods if ya want then find a real sharp cat that can get into your engine and tranny. I've heard some guys say on here they've blown engines because of so and so's PCM tuning. I would honestly say that the popular online PCM guys and I don't have to mention who they are do I. Probably spend 15-30 min with your PCM and then ship it back to ya and the ones off the shelf, don't expect much out of those either. Find someone local who has the equipment and knows your vehicle and let him spend a few hours refining your PCM's parameters. I think all mods have some value in terms of adding power to a car but be cautious how far you go. I don't race my car, I'm willing to bet most of you don't either ya just want a street beast, nothing wrong with that really but make it a stable one. I can go on and on with this but I think ya all get it.

Ugh... why did I read this

[Liquifire]

What did you say? I didn't want to read the rambling. The stock catback is proven to flow efficiently up to 350+FWHP...it isn't restrictive at all. And saying you gain 10hp from a SLP catback is funny.

Maybe he has an LS1 in there........then maybe.