Upgrading the exhaust system on a Mercedes‑AMG W205 C63 is one of the most effective ways to unlock deeper, more aggressive engine notes and gain a modest power increase. The MBRP cat‑back exhaust is a popular choice among enthusiasts because of its T‑304 stainless steel construction, mandrel‑bent tubing, and straight‑through muffler design that reduces backpressure while maintaining a refined tone under cruising conditions. This comprehensive guide provides a detailed, step‑by‑step installation walkthrough, along with tool recommendations, torque specifications, and troubleshooting tips to ensure a clean, leak‑free fit. Whether you are a seasoned DIYer or tackling your first exhaust swap, following these instructions will help you complete the job safely and efficiently.

Tools and Materials Needed

Before lifting the vehicle, gather all required tools and components. Having everything within reach prevents unnecessary delays and reduces the risk of injury from scrambling under the car.

  • MBRP cat‑back exhaust system (confirmed correct for W205 C63, part numbers vary by tip style)
  • Motor oil or anti‑seize compound – for lubricating exhaust hanger rubber and clamp threads
  • Floor jack and two jack stands (3‑ton capacity recommended)
  • Wheel chocks
  • Safety glasses and mechanic gloves
  • Exhaust hanger removal tool or long‑reach slip‑joint pliers
  • 13mm, 15mm, and 18mm sockets with ratchet and extension bars
  • Torque wrench (ft‑lb range for clamp bolts)
  • PB Blaster or similar penetrating oil
  • Dead‑blow hammer or rubber mallet
  • Wire brush – to clean flange surfaces and hanger mounts
  • Rags and a catch pan (stock exhaust may hold a small amount of condensation)

Optional but helpful: an axle stand lift adapter for the pinch weld, a creeper to slide under the car easily, and a drop light for better visibility.

Preparation and Safety

Park the W205 on a level concrete surface. Engage the parking brake and place wheel chocks behind the front tires. Allow the exhaust to cool completely – even after a short drive the catalytic converters and mid‑pipes remain hot enough to cause severe burns. If the car has recently been driven, wait at least one hour before beginning work.

Disconnect the negative battery terminal to avoid any accidental short circuits or electrical faults, especially if you will be near the rear differential or any exposed wiring. While not strictly required for a cat‑back install, it is a best practice that protects the vehicle’s electronics.

Step 1: Lift the Vehicle Safely

Position the floor jack under the rear differential housing (the pumpkin) or under the factory jacking point behind the rear wheel. Slowly lift the rear of the car until the tires are about 8–10 inches off the ground. Place jack stands under the designated lift points on the rear subframe – never under the exhaust or suspension arms. Lower the car gently onto the stands and verify stability by pushing on the bumper. The exhaust work requires access to the entire underside from the catalytic converter flanges back to the tailpipes, so ensure the vehicle is level and secure.

Step 2: Remove the Stock Cat‑Back Exhaust

2.1. Unbolt the Mid‑Pipe Connections

Locate the two flanged connections where the stock exhaust meets the catalytic converters (downpipes). On the W205 C63 these flanges are connected with two 15mm bolts each. Apply penetrating oil to the bolts and let it soak for 2–3 minutes. Using a 15mm socket and a breaker bar if necessary, remove the bolts. Some corrosion is normal; if a bolt feels stubborn, work it back and forth with oil rather than applying full force – snapping a bolt in the flange creates a much bigger repair.

2.2. Detach the Exhaust Hangers

Working from front to rear, locate the rubber exhaust hangers that suspend the factory exhaust from the chassis. There are typically four to six hangers on the W205 C63. Use the exhaust hanger removal tool or a pair of long‑reach pliers to compress the rubber eyelets and slide the metal hanger pins out. An alternative method is to spray the rubber with silicone lubricant and use a flat‑head screwdriver to pry the metal pin free. Be careful not to tear the rubber – reused hangers work fine with MBRP’s system, but torn ones will need replacement.

2.3. Lower the Factory Exhaust

With all hangers disconnected and the flange bolts removed, the stock cat‑back exhaust is only held by the two guide rings near the rear muffler. Have a helper support the mid‑pipe section while you work the tailpipe tips out of the rear bumper cutouts. Slowly lower the complete exhaust assembly to the ground. The factory system is heavy (approximately 40–50 lbs for the W205 C63), so use proper lifting technique – bend your knees and keep your back straight. Slide the exhaust out from under the car and set it aside.

Step 3: Prepare the Install Area

Inspect the flange face on the catalytic converter outlet. Use a wire brush to remove any carbon buildup or rust scale. Wipe the area clean with a rag. If the flange bolts from the factory were badly corroded, replace them with new Grade 8 fasteners from a hardware store – the MBRP kit typically includes new bolts and gaskets, but verify the package contents. Install the new ring gaskets onto the studs (if studs are present) or hold them in place temporarily with a dab of grease.

Check the condition of the rubber hangers. If any are cracked, stretched, or feel brittle, replace them with OEM Mercedes hangers for the best vibration isolation. MBRP hanger isolators are included in the kit, but many builders prefer to keep factory rubber to prevent rattles.

Step 4: Install the MBRP Cat‑Back Exhaust

4.1. Assemble the Mid‑Pipe Section

The MBRP cat‑back exhaust for the W205 C63 ships in multiple pieces: a Y‑pipe (or H‑pipe depending on configuration), two mid‑pipes, and the rear muffler section with tips. Begin by loosely connecting the mid‑pipe section that mates to the catalytic converter flanges. Slide the included band clamps over the tube ends, then insert the pipe into the flange. Hand‑tighten the two 15mm bolts that secure the flange. Do not fully torque them yet – all connections should remain loose to allow final alignment.

4.2. Hang the Rear Section

Slide the rear muffler section under the car and hang it from the existing rubber hangers. Apply a thin coat of motor oil or anti‑seize to the hanger pins to ease installation and reduce future rust. On the W205 C63, the left and right tailpipes exit through the bumper valance; you may need to gently push the tips through the cutouts while a helper supports the muffler from underneath. If the fit is tight, loosen the rear hanger bolts on the MBRP muffler body to allow slight movement.

4.3. Connect the Mid‑Pipes to the Rear Section

With the rear muffler hanging freely, attach the mid‑pipes to the muffler inlet tubes using the supplied band clamps. Orient the clamps so the bolt heads are accessible from the side (not the top) for easier final tightening. Ensure that the pipes do not contact the underbody heat shields or the drive shaft. A common point of interference on the W205 is the heat shield near the rear differential – if the pipe touches, gently bend the heat shield with a pry tool or use a rubber mallet to create clearance.

4.4. Align the Tips

Adjust the tailpipe tips so they are centered in the bumper cutouts and have even gaps on all sides. This is the most aesthetic‑critical step – take your time. Tighten the muffler hanger bolts to 18 ft‑lb (24 N·m) once the tips are perfectly aligned. Then tighten the mid‑pipe band clamps to 30–35 ft‑lb (40–47 N·m). Finally, torque the flange bolts at the catalytic converter to 35 ft‑lb (47 N·m) using a torque wrench to prevent future leaks.

Step 5: Final Checks and Leak Testing

Before lowering the vehicle, double‑check every clamp and bolt. Ensure that no part of the exhaust system is under tension or rubbing against the chassis, fuel lines, or brake lines. Spin the tailpipes by hand – they should rotate slightly but not wobble.

Reconnect the negative battery terminal. Start the engine and let it idle. Carefully feel around each joint with your hand (keeping hands away from moving belts) – any puffing air indicates a leak. An alternative method is to use a spray bottle with soapy water at the flanges and clamps; idling the engine and revving gently will cause bubbles to appear at leak points. Shut off the engine and tighten any suspect connections.

If you hear metallic rattling, the exhaust is likely contacting the body or a heat shield. With the engine off and cool, reach up and gently push on the pipes to identify the contact point. A slight bend of a heat shield or repositioning the hanger isolator usually solves the issue.

Step 6: Lower the Vehicle and Road Test

Once you are satisfied with the fit and absence of leaks, raise the car slightly with the jack, remove the jack stands, and lower it to the ground. Remove wheel chocks. Start the engine and listen for any new sounds – the MBRP system should produce a deeper, more aggressive idle with moderate drone at highway speeds. Take the car for a 10‑minute drive that includes low‑speed turns, acceleration from a stop, and a brief highway stint. After the drive, park and re‑inspect all clamps – heat cycling can cause newly tightened clamps to loosen slightly. Retorque the band clamps and flange bolts if necessary.

Performance Gains and Sound Character

The MBRP cat‑back exhaust on the W205 C63 yields a reported power increase of 6–8 horsepower at the wheels when paired with a tune (significantly less without tuning). More importantly, the sound profile changes dramatically: the factory “inside a pillow” muted tone is replaced by a crisp, European‑style snarl at 3,000 rpm and an angry roar under full throttle. The straight‑through design eliminates the large rear muffler’s baffling, yet the included resonators keep in‑cabin drone at a comfortable level for daily driving. Many owners report improved throttle response and a slightly lighter overall weight – MBRP’s system saves about 12–15 lbs compared to the stock exhaust.

For more details on MBRP’s fitment and warranty, visit their official product page for the W205 C63 system: MBRP W205 C63 Cat‑Back Exhaust. Additionally, the MBWorld W205 C63 Forum is an excellent resource for owner experiences and installation photos. For a video walkthrough, search YouTube for MBRP W205 C63 installation guides – several detailed tutorials are available.

Troubleshooting Common Issues

  • Exhaust hits the driveshaft: Loosen the mid‑pipe band clamps and rotate the pipe until clearance is achieved. If the pipe is still too close, shim the hanger with a thick washer.
  • Tailpipes stick out too far or too short: Slide the rear muffler section forward or backward while the clamps are loose, then retighten. MBRP’s clamps allow about 1.5 inches of adjustability.
  • Noticeable drone between 2,000–2,500 rpm: This is somewhat normal with a straight‑through system. Adding a sound deadening mat in the trunk or installing MBRP’s optional resonator kit can reduce drone.
  • Check engine light appears after install: On rare occasions, the downstream O2 sensors can be affected by altered exhaust flow. Ensure the sensors are properly connected and not damaged during the swap. If the light persists, a tune that accommodates the free‑flowing exhaust is recommended.

Conclusion

Installing an MBRP cat‑back exhaust on your Mercedes‑AMG W205 C63 is a weekend project that delivers immediate audible and performance rewards. By following these detailed steps, you can complete the installation with confidence, avoid common pitfalls, and achieve a professional‑quality finish. The sound upgrade alone transforms the driving experience – the MBRP system balances aggressive tone with daily‑driver civility, making it one of the best value modifications for the C63 platform. Remember to periodically inspect the clamps and hangers during routine maintenance to ensure long‑lasting service. Enjoy the enhanced soundtrack of your AMG V8.