BenzUnited Parts
M276 Catless Downpipes for Mercedes-AMG C43 / E43 / E450 (2015–2023)
M276 Catless Downpipes for Mercedes-AMG C43 / E43 / E450 (2015–2023)
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These high-flow catless downpipes for the M276 3.0L BiTurbo V6 replace the factory catalytic converters, a major bottleneck on the C43 / E43 / E450 platform. Once installed, you'll notice quicker turbo spool, sharper throttle response, and a deeper, harder-edged note under load. +15–20 HP and +20–30 lb-ft on their own, and up to 485 HP / 530 lb-ft when paired with our M276 ECU tune.
Three finishes, one downpipe. All three share the same catless core and flow identically — the difference is how much heat radiates off the pipe into the engine bay. Raw Stainless is untreated 304. Heat Shielded cuts radiant heat from the pipe by up to 70–80%, holding under-hood temperatures down and protecting nearby wiring and sensors — worth it on a daily-driven or hot-climate car. Ceramic Coated sits between the two: a real reduction over bare stainless, though not as effective as full shielding, and it adds flex sections at both ends to absorb engine movement and thermal expansion. Select yours in the selector above.
Real Sound Demo — 485 HP / 530 lb-ft with downpipes and tune
Key Features & Benefits
- Direct Bolt-On — No cutting or fabrication required; installs in 2–3 hours. Professional installation is recommended
- TIG-Welded 304 Stainless Steel — Precision welds and machined flanges for leak-free, factory-spec connections with 3.0″ primary and 2.0mm wall thickness
- Reduced Exhaust Backpressure — Allows the turbos to spool more efficiently and build boost faster under load
- Stronger Mid-Range Torque — Noticeable power gains in the heart of the powerband
Complete the Stage 2 Build
These downpipes are the hardware half of a Stage 2 M276. The tune is what turns them loose — it lets the ECU take advantage of the extra flow, and it clears the check-engine light the catless design will otherwise set.
What Else Owners Add At The Same Time
Downpipes free up the exhaust side. These address the sensor, boost and braking side — worth doing together while the car is already on the lift.
- Sensors: 24″ O₂ sensor extension harness — catless pipes reposition the sensor bungs and factory leads often will not reach
- Boost control: blow-off valve adapter — audible boost release, easy while the intake side is open
- Braking: stainless braided brake lines — firmer pedal to match the extra power; W205 C43 / C450 kit
Compatibility
| Chassis | Years | Models |
|---|---|---|
| W205 Sedan | 2015 | C400 4MATIC |
| W205 Sedan | 2016 | C450 AMG 4MATIC |
| W205 Sedan | 2017–2021 | C43 AMG 4MATIC |
| C205 Coupé / A205 Cabriolet | 2017–2023 | C43 AMG 4MATIC |
| W213 / C238 / A238 | 2017–2018 | E43 AMG 4MATIC |
| W213 / C238 / A238 | 2017–2018 | E400 4MATIC |
| W213 / C238 / A238 | 2019 | E450 4MATIC |
Mercedes renamed this car twice without changing it, which is why the table splits by model rather than running one range. C400, C450 AMG and C43 AMG are the same W205 platform under three names. If your car is on that list, these bolt straight on with no cutting or fabrication.
The C43 Coupé and Cabriolet stayed on this platform two model years longer than the sedan did — we list and stock them through 2023.
What these do not fit. Fitment here is decided by chassis, not by engine. The 2023 and newer C43 Sedan is a different car — it is the W206 chassis with the M139 2.0L four-cylinder. The name carried over, the engine did not, and these will not fit it. They also do not fit the C207 Coupé or A207 Cabriolet, the two-door cars from the previous E-Class generation. These are built for the W205 / C205 / A205 and W213 / C238 / A238 platforms and nothing else.
Warranty, Shipping & Returns
- 12-month structural warranty — covers welds, flanges, and structural integrity under normal street use
- Free U.S. shipping with tracking, shipped next business day from US stock
- 30-day returns — unused and in original packaging. See full return policy →
Frequently Asked Questions
Do these require a tune?
They work well on stock vehicles. A tune is highly recommended for maximum performance and to clear fault codes.
Will I get a check engine light?
Removing the catalytic converters will typically set a catalyst-efficiency code on an untuned car. A tune clears this properly — we do not recommend defeat devices.
Are they catless?
Yes — fully catless. Intended for off-road, track, and racing use only.
What is the difference between the three finishes?
Same catless core, same 3.0″ primary, identical flow on all three. What changes is radiant heat off the pipe. Raw Stainless is untreated 304. Heat Shielded cuts radiant heat by up to 70–80%, which keeps under-hood temperatures down and protects wiring and sensors routed near the exhaust. Ceramic Coated lands between the two — a real improvement over bare stainless but not as effective as full shielding — and adds flex sections at both ends to absorb engine movement and thermal expansion.
Do I need the O₂ sensor extension harness?
Often, yes. A catless downpipe repositions the sensor bungs relative to the factory pipe, and the original leads may not reach comfortably. A 24″ extension avoids stretching or splicing the harness.
Will they fit my exact vehicle?
Check the table above — it splits by model and year because Mercedes renamed this car twice. On the C-Class: C400 is 2015, C450 AMG is 2016, and C43 AMG is 2017–2021 as a sedan and 2017–2023 as a Coupé or Cabriolet. On the E-Class: E43 AMG and E400 are 2017–2018, E450 is 2019. These are built for the W205 / C205 / A205 and W213 / C238 / A238 chassis and nothing else — the 2023 and newer C43 Sedan is a W206 with a four-cylinder and is not covered.
How long does installation take?
Professional shops typically complete the install in 2–3 hours.
Off road use only. Not legal for use on emissions-controlled vehicles or public roads.
