Thread: ZZP Exhaust on 2006 Grand Prix Parts Noob

If this is the totally wrong forum for this please please point me in the right direction


I have a 2006 Grand Prix 3.8 L26 NA, low miles, to upgrade the exhaust would I need to install all of the following at once or can I do one at a time with the OEM system?


https://www.zzperformance.com/3800/e...aders-downpipe


https://www.zzperformance.com/3800/e...less-power-log


https://www.zzperformance.com/3800/e...rear-power-log


https://www.zzperformance.com/3800/e...atback-exhaust


Are these even the correct parts? Is there a catalytic converter being deleted here? I gotta stay Ohio legal. This is the first car I haven't worked on with my Dad, he usually helps with that side of things but he's more into pre-1980 stuff. I have their ZZP PCM chip, coil packs, and 180 thermostat already installed along with K&N cold air intake. I'm thinking exhaust system is next? I plan on doing the HD trans upgrade after that and then swapping the heads and then buying a refurb L32 SC and getting the rest of the parts from a junkyard (upper, lower manifold, etc). Sound like a crazy plan? I already own a Tech2 so I can do any PCM diagnostics or re-calibration necessary.

The links keep bringing me to the same page, but that doesn't matter much.

Well since you're NA, you're pretty much goin for sound only. Not much to gain with all those dollars. I'd skip the power logs unless you just like the shine.

People have differing opinions on what sounds best. I liked my Borla 3" kit the best. Running stock mufflers with a replacement resonator right now, which I also like. For the love of god, don't straight pipe it. Don't be one of those guys on fb raving about how great the idle sounds because you can't afford mufflers. It's obnoxiously loud.

it sounds like he wants to do a top swap. most people just run headers like speed daddy from ebay. it will take more work to install, but at less than half the price, it is worth the extra work.

Ok, so you're gonna want to get the 2.5" ZZP downpipe with cat. you're staying legal so you'll need the o2 harness extension as well. Now is a good time to replace both O2 sensors if you've never done that. If you decide to get the powerlogs at the same time, its a good Idea to get the ARP header bolts too, and of course the exhaust manifold gaskets, as well as a new donut gasket for the crossover if yours looks really worn.
Start by removing the crossover bolts, then the downpipe, then remove the rear exhaust manifold (I removed it from underneath the car). Careful with that EGR tube (mine was crushed during reinstallation and I ended up deleting it entirely). finally remove the front exhaust manifold.
Install gaskets, then install the rear powerlog. install your o2 sensors, followed by the new downpipe. Bolt the crossover to the rear powerlog, and install the front powerlog. Start the car and check for leaks.
The catback isn't necessary at all unless you're boosted and getting a 3 inch system (you're N/A so you'll need that extra backpressure in the 2.5 inch stock setup). If you already have dual exhaust, great. If not, and you want it for looks, just buy some magnaflow mufflers and have a shop weld them up with a y-pipe.
The downpipe with the cat is really the most important part of this setup since you need to stay legal, so make sure you get the right one.

I run a 3" catted ZZP downpipe and front P-log on my 00 GT. I just reused the stock bolts. Nothing fancy there. I didn't loose any power by going 3" since the rest of the system is still the stock pipe diameter. Didn't bother with the rear manifold. Watch the K&N filter as the oil can screw up the MAF.

As far as the "top swap" goes I'd just grab it all from a junkyard. Would be a lot cheaper. Heck, they even show up on here now and then. If you need to tune it then get an HP Tuner or the like. Then throw in some headers and call it done.

Originally Posted by Scottydoggs

Top Swap Info and Faqs, Also lots of 3800 Info read this, and then re read it.

your tech 2 is not gonna re tune the pcm. if your na now your running twice as much timing as a sc set up. so you'll need a re tune.

hd tranny is kinda a waste of money, not needed. only difference is the hd diff. and most like the na gears better then the sc hd tranny gears.

and get the 3 inch down pipe if your plan is to top swap it. might even want to get headers and add a 3 inch 50 dollar ebay hi flow cat to the dp.

Meant using the Tech2 for diagnostic troubleshooting moreso, $40 charge to reprogram my PCM with ZZP isn't bad, not worth spending $500+ on my own HPTuners setup.

Really surprised to hear that about the HD trans, honestly relieved though.

I was thinking I'd go 3-inch anyways because I'd think it would sound deeper, don't want an annoying high pitched drone exhaust.

Originally Posted by SaukRapids

The links keep bringing me to the same page, but that doesn't matter much.

Well since you're NA, you're pretty much goin for sound only. Not much to gain with all those dollars. I'd skip the power logs unless you just like the shine.

People have differing opinions on what sounds best. I liked my Borla 3" kit the best. Running stock mufflers with a replacement resonator right now, which I also like. For the love of god, don't straight pipe it. Don't be one of those guys on fb raving about how great the idle sounds because you can't afford mufflers. It's obnoxiously loud.

They just revamped their site so links are a little broken, definitely not going for sound only I was under the impression the stock exhaust was too restrictive on these engines and opening up the front powerlogs can add horsepower even in a NA system, but that might be bs. Definitely won't straight pipe it, I love these cars I'd rather gouge my eyes out. I'd rather spend the money for a deeper sounding system, but I'd rather go for an HP gain over anything.

Originally Posted by FordMan77

I run a 3" catted ZZP downpipe and front P-log on my 00 GT. I just reused the stock bolts. Nothing fancy there. I didn't loose any power by going 3" since the rest of the system is still the stock pipe diameter. Didn't bother with the rear manifold. Watch the K&N filter as the oil can screw up the MAF.

As far as the "top swap" goes I'd just grab it all from a junkyard. Would be a lot cheaper. Heck, they even show up on here now and then. If you need to tune it then get an HP Tuner or the like. Then throw in some headers and call it done.

I was thinking about wrenching as much as I can off of an L32 and have ZZP reflash me to the GTP image (only $40 for reflash since they did my original tune, cheaper than $500 for HPTuners lol.)


Do you think I should just not oil the K&N filter then? I don't really get what the oil does if I clean it regularly unless it makes it aqua-phobic or something.

Originally Posted by SgtMarshal

it sounds like he wants to do a top swap. most people just run headers like speed daddy from ebay. it will take more work to install, but at less than half the price, it is worth the extra work.

The headers are half the price of powerlogs?

Originally Posted by icechains55

Ok, so you're gonna want to get the 2.5" ZZP downpipe with cat. you're staying legal so you'll need the o2 harness extension as well. Now is a good time to replace both O2 sensors if you've never done that. If you decide to get the powerlogs at the same time, its a good Idea to get the ARP header bolts too, and of course the exhaust manifold gaskets, as well as a new donut gasket for the crossover if yours looks really worn.
Start by removing the crossover bolts, then the downpipe, then remove the rear exhaust manifold (I removed it from underneath the car). Careful with that EGR tube (mine was crushed during reinstallation and I ended up deleting it entirely). finally remove the front exhaust manifold.
Install gaskets, then install the rear powerlog. install your o2 sensors, followed by the new downpipe. Bolt the crossover to the rear powerlog, and install the front powerlog. Start the car and check for leaks.
The catback isn't necessary at all unless you're boosted and getting a 3 inch system (you're N/A so you'll need that extra backpressure in the 2.5 inch stock setup). If you already have dual exhaust, great. If not, and you want it for looks, just buy some magnaflow mufflers and have a shop weld them up with a y-pipe.
The downpipe with the cat is really the most important part of this setup since you need to stay legal, so make sure you get the right one.

This sounds pretty straightforward, but if I plan on top-swapping or running turbo in the future should I go ahead and at least run a 3" downpipe?

You can run a K&N, just don't overload it with oil as it can coat the wires in the MAF sensor and cause issues. I think AEM makes a dry flow one if you feel the need to upgrade the filter.

Injen also makes a good dry filter. Made in USA.

Those SD headers: A couple weeks back in one of the fb groups a guy showed his crossover. I'd hope there's a new batch, cus damn.. that thing musta been off by like 4 inches, lol. If the engine's out it's easier. You'll still want new band clamps, and a new flex for if (when) it'll go bad. If you want the bottom "hump" taken out on the header downpipe, that'll cost even more. Personally, I'd wait until you got all your other mods done. If you still got a pesky degree of knock or two, headers will help kill it.

Where are you going with this build? Probably won't outflow stock manifolds till over 325 wheel hp +/-

Originally Posted by Scottydoggs

sadly being made in china the sd headers do sometimes come with a poorly bent cross over pipes. used is always a good choice, at least you know they fit on another car already.

Those are a lot cheaper than I expected, and thanks for the tip on buying used.

Originally Posted by SaukRapids

Injen also makes a good dry filter. Made in USA.

Those SD headers: A couple weeks back in one of the fb groups a guy showed his crossover. I'd hope there's a new batch, cus damn.. that thing musta been off by like 4 inches, lol. If the engine's out it's easier. You'll still want new band clamps, and a new flex for if (when) it'll go bad. If you want the bottom "hump" taken out on the header downpipe, that'll cost even more. Personally, I'd wait until you got all your other mods done. If you still got a pesky degree of knock or two, headers will help kill it.

Where are you going with this build? Probably won't outflow stock manifolds till over 325 wheel hp +/-

325-350 is around where I want to end up. Any recommendations on headers? ZZP has them but they're pretty expensive.

I'm N/A and planned on staying that way for a while, which is why I stuck with the 2.5 inch exhaust all the way through. If you plan on going Turbo or staying N/A, buy the Powerlogs and the 2.5 inch DP with cat. They will work better with a turbocharged setup. Not even sure if you can run headers with a turbo. If you plan on top swapping and going supercharged, get the headers and a 3 inch DP with cat. I would suggest paying the extra money for good headers. The welds will be good and strong, and wont require any modifications to fit, and theyll look good for a long time. SD headers are chinese, and usually suck unless somehow you got a set out of a good batch.

Ill eventually go Turbo, but honestly after all the trouble I had with Overkill, and eventually ZZP with the tune that I wanted, I'm not ever looking forward to disconnecting my PCM again lol. which is disapointing as hell after all the great stuff I heard about Overkill tunes. but Overkill is like the Olympics, Will only respond to emails once every 4 years. usually not at all.

Originally Posted by icechains55

I'm N/A and planned on staying that way for a while, which is why I stuck with the 2.5 inch exhaust all the way through. If you plan on going Turbo or staying N/A, buy the Powerlogs and the 2.5 inch DP with cat. They will work better with a turbocharged setup. Not even sure if you can run headers with a turbo. If you plan on top swapping and going supercharged, get the headers and a 3 inch DP with cat. I would suggest paying the extra money for good headers. The welds will be good and strong, and wont require any modifications to fit, and theyll look good for a long time. SD headers are chinese, and usually suck unless somehow you got a set out of a good batch.

Ill eventually go Turbo, but honestly after all the trouble I had with Overkill, and eventually ZZP with the tune that I wanted, I'm not ever looking forward to disconnecting my PCM again lol. which is disapointing as hell after all the great stuff I heard about Overkill tunes. but Overkill is like the Olympics, Will only respond to emails once every 4 years. usually not at all.

The contact I have at ZZP luckily seems pretty excited to help me with anything on the PCM side, so at least I'll have that. I'll probably start saving up for good headers and a 3" downpipe then. I feel like adding a turbo might get too expensive and complicated (never done one before) while the L26/32 swap is well documented. I'd probably rather put a turbo on my 93 Trans Am first