ZZP 3800 Downpipe

Exhaust - ZZP 3800 Downpipe

ZZP 3800 Downpipe

297 reviews
Regular price $229.99
  • In stock, ready to ship
  • Inventory on the way

The stock downpipe uses double-walled tubing with an inside diameter of just over two inches. Following the restrictive downpipe section, the stock unit subjects the exhaust gases to the choking effects of the catalytic converter. After the cat, it flattens out into a section dubbed the infamous "U-Bend," which is a section of pipe crushed into a "U" shape by GM in order to fit a rear o2 sensor. This section has less volume than the same length of 2" pipe, and approaches the volume of a 1.75" pipe with the rear o2 sensor in place! Our downpipe eliminates all of the aforementioned problems! Gains of over 15HP have been seen, along with a substantial drop in knock. Most users can drop a pulley size and/or eliminate 5-7 degrees of knock. This part can typically be installed in under an hour.

All downpipes are sold with a high flow catalytic converter. 

Our downpipes are made from high quality stainless steel. Even the flanges are stainless, which isn't something any other company offers. All welds are held to the strictest of quality control standards to ensure a professional finish. Our Weld quality is higher than any other downpipe manufacturer. When shopping around, ask if the downpipe is 100% stainless, ask if they use stainless and for a close up shot of their welds. Compare them to ZZP's, and it will be apparent why ZZP's downpipes are leaps and bounds ahead of the competition. They are guaranteed leak free and feature high quality welds, laser cut flanges and 16 gauge metal. We have test-fitted our bolt-in pipes on both stock and modified cars with perfect fitment. Our pipes even include the slight factory angle offset on the flange.

Interlock flex, sometimes called turbo flex is the best flex money can buy. Typically, the downpipes in our market use a single wall flex. This is durable but has a ribbed inside design that can disrupt airflow. This type of single wall flex is what people are running when you hear them complain about a whistling or ticking noise coming from their exhaust section. To remedy these issues, you can buy a double braided flex which has braided stainless on the inside, as well as outside, of the flex. The problem is that they fail very easy on supercharged cars. Interlock flex is the 3rd solution and while is costs more, it is the best possible option. It withstands the higher temperatures of boosted applications and provides a flat smooth surface for the exhaust gas to run over. 

Most common downpipe gaskets can be found here, exhaust manifold to downpipe inlet gasket, downpipe to factory catback/2.5" catback gasket.

04+ Grand Prix' (Series III cars) will require a style "B" o2 extension for the rear o2 sensor. 

Please use factory torque specs when installing our downpipes.

This downpipe is not compatible with any aftermarket headers, it is designed to fit the stock OEM rear manifold.

*Shipping charges are based on dimensional weight


This will only fit the 3800 v6 engine, does not fit LS4 V8 cars, if you have an LS4 powered car, you would want our "GXP" downpipe instead.

This fits on all the following cars:

  • 1997-08 Pontiac Grand Prix with 3800 Series II engine-Both Supercharged and Non-Supercharged cars
  • 2000-05 Monte Carlo 3800 3.8L Engine Only
  • 2000-05 Impala 3800 3.8L Engine Only
  • 1997-04 Regal 3800 3.8L Engine Only
  • 1998-99 Intrigue 3800 3.8L Engine Only

Our downpipes come with a high flow catalytic converter that is 48 state legal. Our catalytic converters will not pass California or New York state emissions. Please contact customerservice@zzperformance.com if you have any questions.

We are currently offering $100 in store credit to purchase your stock catalytic converter back from you. If you're interested, take a photo of your stock downpipe and email it to Henry@zzperformance.com. We will provide prepaid shipping labels for domestic (U.S.) shipments.

Customer Reviews
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Rob M.
United States

Truth be told.

I absolutely appreciate ZZP as there aren’t many options for W body guys. I am new to the W body scene after owning and building over 30 cars easy. I bought the Intimidator because it was a nice car that I liked. However, support and information from ZZP isn’t the greatest. Every other car I own I am able to call and speak to someone about the plans and progress of the vehicle I am spending money in their store on. ZZP doesn’t answer the phone, returns are penalized even if you’ve spent thousands, and your sort of treated like a dreamer or I get the feeling they think you’re wasting their time. That doesn’t happen in the classic automotive world and it’s because the cars are more expensive and the customers spend lots of money. I will be going back to a classic ASAP and keep this intimidator not far from where it’s at. It’s just not worth building a car with the lack of support you get in the W body world. FWIW, I’ve probably spent 3 grand with this company in the past 2 months I’ve owned the car and I had big plans for it. Now I’m considering doing a professional back halved RWD conversion so I can keep the car and change the companies I deal with. Email takes too long to convey information and the conversations are slower. You cannot fully get all the ins and outs of every detail. It’s disappointing. I still think out of w body world, ZZP is your best bet as they at least strive to keep making parts for these cars and seem to have the best financial backing to keep pushing the platform. Thanks.

James P.
United States United States

Excellent value!

2000 monte carlo. Great quality, fit was perfect! Very impressed!

A ZZPerformance Customer
Ralph Stacy, Jr.
United States United States

Great fit with the ZZP Rear Power Log

Nice quality and performance... even in states that you shouldn't necessarily have them. (wink wink)

United States United States

priced right match w zzp exhaust and performance achieved

1400 buck lifetime exhaust pricey but no muss no fuss and most important in ILLinois no RUST

John P.
United States United States

Zzp 2.5" downpipe review

This install was super easy. Just put the car on wheel ramps used an impact gun with several extensions out with the old in with the new.

ZZPerformance ZZP 3800 Downpipe Review
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