Stone Exhaust Mercedes-Benz M274 W205 S205 C205 Cat-Back Valvetronic Exhaust System for C200, C250 and C300 — Part No. MP505S
Upgrade your Mercedes-Benz C-Class with the Stone Exhaust Cat-Back Valvetronic Exhaust System. Purpose-built for the M274 and M264 engines on the W205 saloon, S205 estate and C205 coupé, this valved, switchable cat-back delivers a deeper, sportier tone, reduced drone and proven performance gains, all with OEM-level fitment and quality. If you are searching for Mercedes W205 exhaust, Mercedes C300 exhaust, C200 cat back, C250 cat back, Mercedes C-Class performance exhaust, or valvetronic valved exhaust UK, this is the system enthusiasts choose.
Developed since 1998, Stone Exhaust begins every system with 3D scanning and reverse engineering of the OEM exhaust to ensure precise, 100 percent OEM fitment. In-house dyno development refines flow, backpressure and sound for your Mercedes-Benz C200, C250 and C300. We have installed and run this system ourselves at Nforcd and our customers consistently praise the sound quality, build precision and everyday drivability.
Why choose this Stone Exhaust cat-back for your W205, S205 or C205?
- Valvetronic valve control for quiet cruising and aggressive sound on demand
- Remote control with ON, OFF and AUTO modes for instant switching
- Plug and play OBDII/OBD2 controller, no complicated wiring
- One-piece precision-bent sections for optimal flow and easy installation
- Eliminates the drone commonly found on the standard exhaust
- 3D scanning and reverse engineering for perfect OEM-style fitment
- In-house dyno developed for real performance improvements
- High-precision mechanical welding and direct spot welding for strength and longevity
Valvetronic control, your way
The Stone Valvetronic system gives you complete control. Open or close the valve at the click of a button, or set AUTO to open at your chosen RPM for a truly tailored Mercedes W205 exhaust experience. The plug and play controller connects at the OBDII port for fast, clean installation.
OPF delete option included
Running an OPF-equipped model? Stone provides an OPF delete option free of charge to allow fitment without triggering error codes. No ECU coding is required. Check local regulations and use responsibly in your region.
Engineered for performance and reliability
Stone’s R&D process uses 3D simulation to analyse exhaust gas flow, temperature and pressure zones, iterating until the optimal result is achieved. A 7-axis CNC bending machine delivers up to 98 percent roundness with minimal outer-bore wear at tight radii, helping prevent flow disturbance and weld fracture. Crisscross and overlapping weld techniques increase penetration and width at high-heat junctions, while direct spot welding by mechanical arms ensures precise, repeatable quality.
Compatibility — Mercedes-Benz C-Class M274 and M264
Mercedes-Benz C-Class:
- W205 C200 7G-TRONIC PLUS (2014+)
- W205 C250 (2014+)
- W205 C300 and C300 4MATIC (2014+)
- S205 C200 and C200 7G-TRONIC PLUS (2014+)
- S205 C250 (2014+)
- C205 C200, C200 7G-TRONIC, C200 9G-TRONIC 4MATIC (2016+)
- C205 C250 (2016+)
- C205 C300 (2014+)
Fitting and installation
Professional fitting recommended. For expert installation, book with Nforcd in Warwickshire. Request a fitting quote at Sales@nforcd.com.
Part number and warranty
Part Number: MP505S
Manufacturer: Stone Exhaust
Warranty: Stone Exhaust 2 Year Warranty
Photos and videos
Stone Valvetronic system overview
R&D and manufacturing
Sound and installation videos
Mercedes W205 C300 M274 x Stone Exhaust cat-back sound
Stone Valvetronic system install overview
Search-friendly terms
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