The Mitsubishi Eclipse of the second generation (1995–1999) remains a darling of the tuner world, offering a robust 4G63 turbocharged platform in the GSX and GST trims. Among the most revered bolt-on upgrades for this chassis is the GReddy Trust exhaust system. More than just a muffler swap, a quality cat-back like this one unlocks measurable performance, refines the driving experience, and completes the classic DSM (Diamond-Star Motors) look. In this guide, we’ll walk through what makes the GReddy Trust exhaust a standout choice, the true performance gains owners can expect, a detailed installation walkthrough, and a full cost analysis – because at roughly $1,200, this is a serious investment. We’ll also compare it to competing systems and provide external resources so you can make an informed decision.

The GReddy Trust Exhaust: A Legacy of Engineering

GReddy – the North American division of Trust – has been engineering aftermarket performance parts for Japanese cars since the 1970s. The Trust exhaust line for the 2G Eclipse is built with a specific philosophy: maximize exhaust flow while maintaining a high level of build quality and durability. The system is constructed from T-304 stainless steel with a polished finish that resists corrosion far better than the OEM mild steel. Mandrel-bent piping ensures the exhaust gases travel through a smooth, constant-diameter path – unlike crush-bent pipes that introduce bottlenecks. The straight-through muffler design uses high-flow packing to reduce restriction, and the piping diameter (typically 3 inches) is optimal for the 4G63 engine’s flow demands at moderate to high power levels.

Unlike universal exhaust kits, the GReddy Trust system is vehicle-specific. It bolts directly to the factory catalytic converter or an aftermarket downpipe, requiring no cutting or welding beyond what is needed to remove the old exhaust. The hangers and flanges are precision-welded to align perfectly with the Eclipse’s underbody, preventing rattles or misalignment. The system also retains the stock O2 sensor bung location, which is critical for maintaining proper air-fuel ratio readings when using a piggyback or standalone ECU.

Performance Benefits: More Than Just a Number

Horsepower and Torque Gains

The most often cited benefit of a GReddy Trust exhaust on a 2G Eclipse is a gain of 10–20 horsepower at the wheels. This range is realistic for a turbocharged 4G63 running stock boost levels (around 12 psi) and no other modifications. The exhaust allows the turbocharger to spool more freely because backpressure is drastically reduced. In practice, this means the engine reaches peak torque sooner and holds it longer. Many owners report a seat-of-the-pants improvement in mid-range pull, especially between 3,000 and 4,500 rpm. If your car is equipped with a larger turbo (e.g., 16G, 20G, or a Garrett GT series), the gains can be even more substantial – up to 25–30 whp, simply because a freer-flowing exhaust is required to support higher airflow.

For naturally aspirated Eclipse models (the RS and GS with the 420A engine), the gains are more modest – typically 5–10 hp – but the sound and weight reduction still make the upgrade worthwhile.

Improved Throttle Response and Engine Efficiency

Reducing backpressure does more than just add peak power. The engine can expel spent gases faster, reducing pumping losses. This leads to slightly improved fuel economy during steady-state cruising (highway driving) and a crisper throttle response when you step on the gas. On a well-tuned 2G Eclipse, you may see a 1–2 mpg improvement on the highway, though this is highly dependent on driving habits.

Sound Profile: Aggressive but Civilized

The GReddy Trust exhaust is known for a deep, aggressive tone without excessive drone at highway speeds. At idle it rumbles, and under full throttle it roars – but it does not cross into the obnoxious territory of some straight-pipe setups. The muffler packing is lifetime-warranted in most cases, though over years the sound may become slightly louder as the packing settles. Many enthusiasts describe it as one of the best-sounding exhausts for the 2G platform, especially when paired with a downpipe and cat-delete. For a reference, you can check out this sound clip on YouTube.

Detailed Installation Guide

Installing a GReddy Trust cat-back exhaust is a project that a moderately skilled DIYer can complete in a weekend. The following steps assume you have a 2G Eclipse (turbo or non-turbo – check for hanger differences) and a basic set of tools.

Tools Needed

  • Jack and two jack stands (rear of car only)
  • Short and long 12-mm, 14-mm, and 17-mm wrenches/sockets
  • Breaker bar or impact wrench (rusty bolts)
  • Penetrating oil (e.g., PB Blaster)
  • Optional: reciprocating saw or angle grinder for stubborn bolts
  • Safety glasses and gloves

Step-by-Step Removal of the Stock Exhaust

  1. Prepare the car. Park on a level surface, chock the front wheels, and jack up the rear of the car using the rear differential crossmember or frame rails. Place jack stands under the rear subframe or designated lift points. For safety, also place a jack stand near the front of the cat-back section.
  2. Spray penetrating oil. Apply PB Blaster to all exhaust flange bolts and rubber hanger mounts. Let it sit for 10–15 minutes.
  3. Disconnect the exhaust from the catalytic converter. Use a 14-mm wrench or socket to loosen the two bolts that connect the cat-back to the catalytic converter. On turbo cars, the cat-back also attaches to the catalytic converter flange – same process. If bolts are severely rusted, use the breaker bar. If they snap, you may need to drill and extract them later.
  4. Remove the hanger mounts. There are typically three rubber hangers: one near the front of the muffler, one mid-pipe, and one near the rear axle. Use a pry bar or simply push the rubber ring off the metal hanger stud. The stock system is heavy – have a helper support the exhaust as you release the last hanger.
  5. Lower the stock exhaust. Slide the exhaust out from under the car. If it’s stuck, spray more penetrating oil and wiggle. You may need to cut the old exhaust if it has rusted into two pieces – but in most cases, a 2G Eclipse with a GReddy upgrade is likely not that far gone.

Installation of the GReddy Trust Exhaust

  1. Unbox and familiarize. Lay out all components: main pipe, muffler, gaskets, hardware, and clamps. Verify you have the correct configuration – some GReddy kits come with a separate mid-pipe and muffler section; others are one-piece.
  2. Attach the mid-pipe to the catalytic converter. Place the gasket (supplied or purchase a new OEM-style donut gasket if you have a turbo model) between the cat outlet flange and the GReddy pipe. Hand-tighten the two bolts. Do not torque them fully yet.
  3. Install the hanger mounts. Slide the rubber hangers onto the metal studs on the car. The GReddy system typically uses the same hanger positions as stock. You may need to lubricate the rubber with a bit of dish soap to make them slide on easier.
  4. Connect the muffler section. If the muffler is separate, slip the band clamp over the mid-pipe, then attach the muffler. Ensure the tip aligns nicely with the bumper cutout. Leave the clamp loose enough to allow adjustment.
  5. Align and torque. Once everything is loosely in place, start the car – or just simulate the exhaust position – to ensure there are no contact points with the rear axle, chassis, or trailing arms. Adjust as needed, then torque all fasteners to the manufacturer’s specifications (typically 30–35 ft-lbs for the flange bolts and 40–50 ft-lbs for the band clamp).
  6. Check for leaks. Start the engine and listen for any hissing or ticking around the flange connections. If you hear a leak, tighten further or replace the gasket. Alternatively, use a smoke tester if you have one.
  7. Lower the car. Remove jack stands and lower the car. Take it for a short test drive to settle everything, then re-check the clearance and tightness after a few heat cycles.

For a visual reference, see this detailed DSMtuners forum guide.

Cost Breakdown: The $1,200 Question

At a retail price of approximately $1,200 for the GReddy Trust cat-back exhaust, it sits at the higher end of the 2G Eclipse exhaust market. However, the price reflects the quality of materials, R&D, and brand reputation. Below is a realistic cost projection, including ancillary expenses.

ItemEstimated Cost
GReddy Trust cat-back exhaust (new)$1,100 – $1,300
Gaskets (if not included or replacement)$20 – $40
Hardware (bolts, nuts, hangers if missing)$15 – $30
Professional installation labor (2–3 hours)$150 – $300
Total if you do it yourself~$1,200 – $1,350
Total with professional install~$1,350 – $1,650

Keep in mind that if you are also upgrading the downpipe or removing the catalytic converter, you will need additional parts and possibly a tune. For turbo DSMs, a 3-inch downpipe matched to the GReddy cat-back is highly recommended – that can add another $200–400. You may also want a boost controller or a wideband O2 sensor to dial in the tune. Many owners find that investing in a quality exhaust like the GReddy Trust pays off in reliability and performance, as cheap systems can crack or drone excessively.

You can purchase the GReddy Trust exhaust from authorized distributors such as GReddy Performance Products or trusted vendors like ExtremePSI.

Comparing the GReddy Trust to Other 2G Eclipse Exhausts

The 2G Eclipse market offers several aftermarket cat-back systems. How does the GReddy Trust stack up against the competition?

  • HKS Hi-Power / Carbon-Ti: Similar price range ($1,000–$1,200). HKS uses a different muffler design that produces a slightly higher-pitched tone. The GReddy Trust is generally deeper. HKS systems are also well-built but may require more tweaking for perfect fitment on some 2G models.
  • Apexi N1 Pro / WS2: Apexi exhausts are known for being lightweight and quiet with a unique bellowed mid-pipe. Prices around $800–$1,000. The GReddy Trust offers better flow potential at higher horsepower levels due to its straight-through design.
  • Tanabe Medalion Touring: Produces a very civilized sound, almost OEM-like at idle. Ideal for daily drivers who want minor performance gains. But it costs around $900–$1,100 and does not match the GReddy’s flow for big turbo setups.
  • Megan Racing / OBX / Ebay specials: Much cheaper ($200–$400) but made of lower-grade stainless steel, poorer fitment, and thin flanges that can warp. The GReddy Trust is clearly superior in build quality and longevity.

If you plan to push your Eclipse beyond 400 whp, the GReddy Trust is one of the few bolt-on cat-backs that can support that power level without becoming a restriction. For street-driven cars making 300–400 whp, it is an ideal balance of flow, sound, and durability.

Maintenance and Longevity

Stainless steel exhausts require minimal maintenance. Periodically check the band clamps and flange bolts for tightness, especially after the first few heat cycles. The muffler packing material inside the GReddy Trust will eventually degrade – after about 50,000–60,000 miles you may notice a slight increase in volume. GReddy offers replacement packing or you can have a muffler shop repack it. The polished stainless finish can be kept shining with a quick wipe of metal polish or simply a hose – brake dust does not stick as easily as on painted steel. Avoid automatic car washes with strong brushes, as they may scratch the surface.

If you live in a region with harsh winters and road salt, consider applying a light coating of anti-seize to the flange bolts to prevent future seizing. The exhaust hangers themselves are rubber and can dry out over time – replace them if they become stiff (OEM replacements are under $20).

Final Thoughts: Is the GReddy Trust Exhaust Worth It?

For any 2G Eclipse owner serious about performance, sound, and quality, the GReddy Trust exhaust is a top-tier choice. Its $1,200 price tag is justified by the materials – T-304 stainless steel, precision mandrel bends, and a fitment that is far better than cheaper knockoffs. The gains are real: 10–20 whp on a stock turbo car, better response, and an exhaust note that complements the 4G63’s character. Installation is straightforward for a home mechanic, and the system is designed to last the life of the car.

That said, if your Eclipse is a completely stock daily driver with no plans for further modifications, a lower-cost system like the Apexi WS2 might suit your needs while saving a few hundred dollars. But if you envision a path of upgrades – larger turbo, injectors, intercooler, tuning – the GReddy Trust is one exhaust you will never have to replace. It grows with your build.

Ultimately, the Eclipse community consistently rates the GReddy Trust among the best exhausts for the 2G, whether you are chasing drag strip times, road course lap times, or simply enjoying a spirited drive through canyons. Pair it with a proper downpipe and a tune, and you’ll unlock the true potential of Mitsubishi’s iconic sports coupe.

For more technical data and owner reviews, you can also browse this DSMtuners thread where enthusiasts share dyno sheets and long-term experiences.