Mercedes C63 W205 Catted and Catless Downpipes, A45S Decat Downpipe Guide
For Mercedes enthusiasts, performance isn’t just about the badge — it’s about pushing limits. Whether you own a C63 AMG W205 or an A45S AMG, upgrading the exhaust system with high-performance downpipes can significantly transform your driving experience. In this article, we’ll explore the pros and cons of mercedes c63 w205 catted and catless downpipes, as well as delve into the popular upgrade of a decat downpipe for the Mercedes A45S.
Understanding Downpipes: Catted vs Catless
The downpipe is a vital component of a turbocharged engine’s exhaust system. It connects the turbocharger to the rest of the exhaust piping and plays a major role in regulating exhaust flow and turbo efficiency.
Catted Downpipes: These feature a high-flow catalytic converter which filters harmful emissions while still providing increased performance over stock downpipes. They are more environmentally friendly and often street-legal in many regions.
Catless Downpipes: These eliminate the catalytic converter altogether, resulting in maximum exhaust flow, reduced turbo lag, and noticeable gains in power. However, they are usually not legal for road use in emissions-regulated areas and may trigger check engine lights (CELs) without proper ECU tuning.
Mercedes C63 W205 Downpipes: Which One to Choose?
The W205 generation of the Mercedes-AMG C63 boasts a 4.0L twin-turbo V8 engine. Swapping out the factory downpipes for aftermarket ones is one of the most popular mods among performance junkies.
Catted Downpipes for C63 W205
Catted downpipes are ideal for those who want a balance between performance and legality. These offer:
- Increased horsepower and torque
- Improved turbo spool
- Reduced backpressure
- Less odor and emissions compared to catless versions
- Lower risk of triggering CELs
Brands like Weistec, Armytrix, and Fabspeed offer high-flow catted downpipes with 200-cell sport catalytic converters, maintaining emissions compliance in many countries while still offering substantial performance gains.
Catless Downpipes for C63 W205
If you’re heading to the track or don’t mind the legal risks, catless downpipes are a solid option for pure performance:
- Loud, aggressive exhaust note
- Faster turbo spool-up
- Higher horsepower gains
- Lower cost than catted options
However, due to increased emissions and possible legal implications, catless downpipes are typically recommended for off-road or racing use only.
Mercedes A45S Decat Downpipe: Small Engine, Big Gains
The A45S AMG features a 2.0L turbocharged engine that punches well above its weight. Installing a mercedes a45s decat downpipe is a proven way to enhance its already thrilling performance.
This upgrade offers:
- Noticeable gains in horsepower and torque
- Dramatic improvement in exhaust tone and turbo sounds
- Quicker turbo response
- Weight reduction over the stock system
But just like with the C63, removing the catalytic converter means the car will not pass emissions in most regulated areas. A software remap or ECU tune is strongly recommended to optimize performance and eliminate CELs.
Tuning After Installation: A Must
Whether you opt for catted or catless downpipes, an ECU remap or tuning session is essential. Not only does it allow you to maximize power gains, but it also ensures your Mercedes runs safely and efficiently. Most tuning companies offer packages specifically tailored for downpipe modifications.
Final Thoughts
Upgrading your downpipe is one of the best performance mods for any AMG. The Mercedes C63 W205 catted and catless downpipes offer different benefits depending on your goals — whether you want street legality or full-throttle power. Meanwhile, the Mercedes A45S decat downpipe proves that even a compact AMG can roar louder and run harder with the right upgrades.
Make sure to always check local emissions regulations before installing aftermarket downpipes, and consult a professional tuner to complete the setup for maximum reliability and performance.
