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M177 Catless Downpipes for Mercedes-AMG GT 63 (X290) & E63 / E63S (W213) – 304 Stainless Steel
M177 Catless Downpipes for Mercedes-AMG GT 63 (X290) & E63 / E63S (W213) – 304 Stainless Steel
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These 304 stainless steel catless downpipes replace the restrictive factory catalytic converters on the M177 4.0L BiTurbo V8, fitting the AMG GT 63 and GT 63 S (X290) and the E63 and E63 S (W213). Once installed, you'll notice quicker turbo spool, sharper throttle response, and a considerably harder exhaust note. 3.0″ outer diameter, 1.5mm wall, 8.5mm high-temperature TIG welding — bolt-on V-band design, installed in 2–3 hours with no cutting.
Want thermal shielding? Select Heat Shielded in the selector above. The shielding cuts radiant heat off the pipe by up to 80%, holding under-hood temperatures down and protecting wiring and sensors routed near the exhaust — worth it on a daily-driven or hot-climate car.
Real M177 Exhaust Sound
With tune + these downpipes
Downpipes only (stock tune)
Key Features & Benefits
- 3.0″ OD, 1.5mm Wall 304 Stainless — Diameter matched to what the M177 actually flows, keeping exhaust gas velocity high enough to protect mid-range response rather than chasing a bigger number on paper
- 8.5mm High-Temperature TIG Welding — Wide, fully penetrated weld beads at every joint, with machined flanges for leak-free factory fitment
- Bolt-on V-Band Design — Simple installation in 2–3 hours with no cutting or modifications required
- Reduced Exhaust Backpressure — Allows the turbos to spool more efficiently and build boost faster under load
Complete the Stage 2 Build
These downpipes are the hardware half of a Stage 2 M177. 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.
Compatibility
| Chassis | Years | Models |
|---|---|---|
| X290 | 2019–2023 | AMG GT 63 4-Door Coupe |
| X290 | 2019–2023 | AMG GT 63 S 4-Door Coupe |
| W213 | 2017–2023 | E63 AMG S |
| W213 | 2016–2020 | E63 AMG |
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'll run on a stock car, but a tune is strongly recommended — both to get the full benefit and to clear the fault codes that catless pipes typically set. There's a sound clip of both configurations above so you can hear the difference.
Will I get a check engine light?
Likely, on the stock tune. Removing the cats means the downstream O₂ sensors read differently than the ECU expects. A tune resolves it properly — we do not recommend defeat devices.
Why 3.0″ and not larger?
Bigger is not automatically better. A downpipe sized past what the engine actually flows drops exhaust gas velocity, and velocity is what carries mid-range torque and turbo response. 3.0″ is what the M177 wants to balance top-end flow against the mid-range you actually drive on.
Is the heat shielding worth it?
On a daily-driven car or in a hot climate, yes. The shielding cuts radiant heat off the pipe by up to 80%, which holds under-hood temperatures down and protects wiring and sensors routed near the exhaust. On a dedicated track car with cooling already sorted, Raw Stainless is usually enough.
Are these street legal?
No. These delete the primary catalytic converters. They hold no CARB Executive Order, are not 50-state legal, and are not legal to install on a vehicle registered or operated on public roads in the United States. They are sold for closed-course competition and off-road use only — see the emissions notice at the top of this page.
How do I know they fit my car?
These fit the M177 BiTurbo V8 in the AMG GT 63 and GT 63 S (X290, 2019–2023), E63 AMG (W213, 2016–2020), and E63 AMG S (W213, 2017–2023). Fitment is decided by chassis, not by engine code. If your car is on that list, it bolts straight on with no cutting.
How long does installation take?
2–3 hours at a professional shop. It's a bolt-on V-band design — no cutting or modification required.
What's included?
A pair of 304 stainless steel catless downpipes with machined flanges and V-band clamps.
Off road use only. Not legal for use on emissions-controlled vehicles or public roads.
