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M278 Catless Downpipes – Mercedes E550 W212 (2012–2016) & CLS550 C218 (2012–2018) 4.7L V8 BiTurbo
M278 Catless Downpipes – Mercedes E550 W212 (2012–2016) & CLS550 C218 (2012–2018) 4.7L V8 BiTurbo
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Off-road, track, and competition use only. May not comply with local emissions regulations. Buyer is responsible for compliance with local laws.
Upgrade your Mercedes M278 BiTurbo V8 with these high-flow catless downpipes. Designed for the 2012–2016 E550 (W212) and 2012–2018 CLS550 (C218), they significantly reduce exhaust restriction for faster turbo spool, improved throttle response, and a deeper, more aggressive exhaust note.
Key Benefits
- High-flow catless design — reduces backpressure at the turbo outlets for quicker boost response and stronger mid-range power
- Direct bolt-on fitment — no cutting or modifications required; replaces the factory catalytic converters
- Deeper exhaust note — more aggressive tone under load with minimal drone during cruising
- +118 hp / +190 lb-ft — with these downpipes and ECU calibration
Complete the Build
A catless setup will typically set a check-engine light without proper calibration. The tune is what turns the hardware loose — it lets the ECU use the extra flow and clears the fault codes properly.
Vehicle Compatibility
| Years | Model | Chassis | Engine |
|---|---|---|---|
| 2012–2016 | E550 (RWD and 4MATIC) | W212 | M278 4.7L BiTurbo V8 |
| 2012–2018 | CLS550 (RWD and 4MATIC) | C218 | M278 4.7L BiTurbo V8 |
Check your engine, not just your badge
2010–2011 E550 cars use the M273 5.5L naturally aspirated V8, not the M278 BiTurbo. These will not fit those cars. The M278 arrived for the 2012 model year.
Driving an E63 or CLS63 AMG? Those use the M157 5.5L BiTurbo and need the M157 downpipes →
If your car is on that list, these bolt straight on with no cutting. Not sure? Send us your VIN and we'll confirm before you order.
What's Included
Complete left and right downpipe set as pictured. Hardware and gaskets are not included unless shown.
Installation
Direct bolt-on replacement. Average install time 1.5–2.5 hours; professional installation recommended. Re-check for leaks after the initial heat cycles.
Frequently Asked Questions
Will these fit my E550 or CLS550?
Yes — a direct fit for the 2012–2016 W212 E550 and 2012–2018 C218 CLS550 with the M278 BiTurbo V8, in both rear-wheel drive and 4MATIC. They do not fit 2010–2011 E550 models, which use the naturally aspirated M273 5.5L V8.
Do I need a tune?
Strongly recommended. Most owners add ECU tuning to avoid check-engine lights and unlock the flow the hardware now allows.
Will I get a check engine light?
Likely, on an untuned car. Removing the cats means the downstream O₂ sensors read differently than the ECU expects. A calibration resolves it properly — we do not recommend defeat devices.
What performance gains can I expect?
Faster turbo spool, sharper throttle response, and stronger mid-range torque on their own, and +118 hp / +190 lb-ft once paired with ECU calibration. Exact figures depend on your calibration and supporting modifications.
Will they work with aftermarket exhausts?
Yes — designed to work with both factory and aftermarket mid-pipes.
Is there a warranty?
Yes — a 12-month structural warranty, with guaranteed fitment on every model listed above.
Buy With Confidence
- 12-month structural warranty with guaranteed fitment on listed models
- Free U.S. shipping with tracking on every order
- Fitment confirmed before you buy — send your VIN and we'll verify before you order
- Mercedes specialists — we focus exclusively on Mercedes platforms and know the M278 inside out
- Real support — questions before or after purchase go straight to us, not a call center
Confirm fitment or ask a question →
BenzUnited Parts • M278 Catless Downpipes • 12-Month Warranty • Ships Fast
