42DD Mk4 2.5" & 3" Flanged Cat-back Exhaust Systems

Starting at: $480.00

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Pipe Size

Tip Type

Stainless Steel

All-out power and sound for the 1.8T!

Attention to detail is what we do at 42, and that certainly shows in the design and construction of our 2.5" & 3" cat-back exhaust systems. From the hardware to the tip fitment it's clear upon installation that we've done our homework. Years of extensive development and long-term testing have gone into these systems. The end result is a cat-back system that fits great, sounds amazing, and adds hp & torque.

Designed to bolt to our 1.8T 3" downpipes, our 2.5" & 3" cat-back systems begin with a CNC machined flange that connects to your existing downpipe. After this flange, an oxygen sensor bung allows for installation of the post-cat oxygen sensor. In a straight shot our system bolts to your downpipe and slides into the first hanger, while a resonator removes rasp from the exhaust note. Next, our system makes the bend around the gas tank and over the rear axle. Fitment in this area is crucial. Our over-axle pipe is bent correctly and built correctly to avoid rear axle rubbing on the lowest cars. Next, a Magnaflow muffer is tucked into the heat shields, almost hidden from view. To finish the system off we have three tip variations available for Jetta and GTI models - hidden, single, and dual. Our tips not only look amazing, but fit perfectly as well. Our tips are made in-house from 304 stainless steel and polished to a mirror finish.

Our relentless attention to detail is proven by the fitment of our 2.5" & 3" cat-backs. Our flanges are CNC machined in house from 1018 cold roll steel. Adjustable flanges are used where appropriate to allow each section to bolt-up as designed on every car. Hangers bars are precisely bent to slide into the factory hangers straight and level. At the rear hanger we include two collars designed to lock the position of the rear muffler in place. Once you've adjusted your tip fitment - keep it there! Each and every system is built by hand on production tooling and TIG welded. All hardware needed for installation is included - gaskets, bolts, washers, and locknuts. We use mechanical locknuts to assure your system never vibrates loose.

The sound of our systems has been imitated since the first sound clips hit the internet. We describe the sound as "quiet when you need to be and loud when you want to be." At idle, the car emits a deep rumble. At low rpms and crusing speeds the sound is mellow and quiet. The exhaust opens up at full throttle and high rpms with a great tone and not a hint of rasp or drone. We tested various resonator and muffler conbinations before finding the perfect balance of power and sound.

While all of our long-term testing was done on 1.8T vehicles, this system will also fit turbocharged 2.0, VR6, and even TDI equipped mk4 VWs. Fitment is designed to connect to your existing 3" downpipe. The system will bolt-up perfectly to our 1.8T 3" downpipes, but we also accomodate other brands of 3" downpipes and custom downpipes by including an extra flange. This flange is intended to be welded to the end of your existing 3" downpipe. Precise fitment of our flange to your existing downpipe is necessary in order to fit this cat-back correctly. While this may seem like a hassle, it is necessary for us to assure a perfect fit. Keep in mind, these cat-backs are designed for factory and custom turbocharged vehicles (1.8T, 2.0T, VR6T). 3" piping is beyond overkill for all-motor applications and not recommended by 42. Our flanged system is designed to bolt-up to our 1.8T 3" downpipes and allow custom fitment to any 3" downpipe on any motor.

Horsepower and torque gains for these cat-back systems cannot be accurately reported as a nominal gain. These cat-backs can be installed on a wide range of vehicles - from a 200whp 1.8T to a 500whp VR6 turbo. Power gains always depend on turbo size, tuning, and what you're replacing.

Our 2.5" & 3" cat-back systems are available in 3 tip configurations and 2 styles to fit Jetta and GTI models. Our single tip GTI system includes a 4" tip designed to fit the 337/20th valance. Our single tip Jetta system includes a 4" tip designed to fit the GLI single tip valance. Our dual tip GTI and Jetta systems include a pair of 3" tips spaced to fit perfectly within the stock valance. These systems fit all models from 2001+ with the factory dual-tip valance. We offer a hidden tip model for both GTI and Jetta models. Hidden tip systems dump exhaust gases before the start of the rear valance. Height and angle of the cut is designed to reduce drone and not melt the valance. The hidden tip is exposed only 1/2" below the bottom of the valance. Truely hidden.

Cat-back pricing starts at $460 and varies by pipe size and tip fitment. Full turbo-back systems are available for 1.8T models in street and race configurations. All configurations can be purchased ceramic coated. Follow the order button below to review available options and fully configure your system.

Construction Highlights

  • CNC mandrel bent 14 gauge aluminized steel tubing
  • CNC machined 1018 cold roll steel flanges
  • Professional TIG welded construction throughout
  • Magnaflow resonator & muffler
  • 304 stainless steel polished tips
  • Double layer graphite gaskets
  • Grade 5 locking hardware

Fitment Details

  • Fits 1999-2005 VW Mk4 Golf, Jetta, GTI
  • Fits 2.0, 1.8T, 12v VR6, 24v VR6, & TDI
  • Reduced to fit stock sleeve clamp
  • Adjustable flanges allow for precise fitment on every vehicle

Available Options

  • Vehicle Fitment
  • Tips
  • Ceramic Coating

Product Spotlight: Single Wall vs. Double Wall Tips
Product Spotlight: Ceramic Coating

  • Model: EX-04-2XXXX
  • Shipping Weight: 42lbs
  • Manufactured by: 42 Draft Designs


This product was added to our catalog on Sunday 29 July, 2012.

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