When you’re talking about squeezing every last drop of performance from your Mercedes-AMG, one of the first mods that comes to mind is the downpipe. Whether you’re driving the thunderous C63 W205 or the agile A45S, upgrading your downpipe can completely change how your car sounds, feels, and performs. But there’s always the big question—catted or catless?
In this guide, we’ll dive deep into the world of mercedes c63 w205 catted and catless downpipes and explore what makes the Mercedes A45S decat downpipe such a game-changer. Whether you’re tuning for track days or just want that signature AMG roar on the street, we’ve got the insights you need.
Why Downpipes Matter for Performance
The downpipe is the section of your exhaust system that connects the turbocharger to the rest of the exhaust. It’s where a lot of exhaust restriction occurs, especially in modern turbocharged engines. When you upgrade this part, you’re essentially freeing up your engine’s ability to exhale—and in turn, it breathes better, revs faster, and builds power more efficiently.
With stock downpipes, especially those containing restrictive catalytic converters, your AMG isn’t performing to its full potential. Enter the catted and catless aftermarket options.
Mercedes C63 W205: Catted vs Catless Downpipes
Let’s start with the beast—your C63 W205. Packing a 4.0L twin-turbo V8, it’s already a powerhouse. But if you’re craving more, a downpipe swap is one of the best bolt-on upgrades you can do.
Catted Downpipes: These downpipes still include a catalytic converter, but a high-flow version. This means:
- Less backpressure than stock
- Maintains emissions compliance (in most places)
- Reduced smell and smoke
- Slightly quieter than catless options
They’re ideal for daily drivers who want improved performance without drawing too much attention or dealing with check engine lights.
Catless Downpipes: These completely eliminate the catalytic converter, offering:
- Maximum power and turbo spool
- That aggressive, raspy AMG growl
- Lower EGTs (exhaust gas temps)
- Lighter weight and simpler flow path
However, catless downpipes often trigger CELs (check engine lights), smell more, and are typically not emissions-legal. But if you’re building a track-focused C63, the performance gains are worth it.
Whether you go for a Mercedes C63 W205 catted and catless downpipes setup is ultimately up to your needs—daily comfort or track performance.
Mercedes A45S Decat Downpipe: Small Car, Big Sound
Now, let’s shift to the mighty hot hatch—the Mercedes-AMG A45S. With a 2.0L turbocharged four-cylinder punching above its weight class, it’s a true performance marvel. And the best way to release that angry soundtrack and turbo responsiveness? A decat downpipe.
A mercedes a45s decat downpipe transforms how this car behaves. Here’s what you can expect:
- Noticeable horsepower and torque gains
- Faster turbo spool (you’ll feel it immediately)
- A raw, louder exhaust note—think rally car vibes
- Reduced backpressure
Because the A45S is so compact and tightly engineered, the downpipe makes a significant difference. It’s a simple mod with huge results—but again, keep in mind emissions and legality depending on where you live.
Should You Tune After Installing a Downpipe?
Absolutely. Installing a downpipe—especially a catless or decat version—will change your air/fuel ratios and increase airflow. Pairing it with a proper ECU tune is crucial to:
- Unlock full performance gains
- Prevent engine knock or lean conditions
- Clear any CELs from missing catalysts
- Customize features like burbles or flames
Without tuning, you’re only enjoying part of the benefit and potentially putting your engine at risk.
Final Thoughts
Whether you choose catted or catless for your C63 W205 or go full decat on your A45S, the performance jump is real. Downpipes are one of the best upgrades for any AMG enthusiast looking to enhance both sound and power. Just be mindful of local emissions laws and always pair hardware upgrades with proper tuning.