Exhaust› Exhaust Pipes, Systems and Components
APR Tuning
Catback Exhaust System S4 / S5 (B9) Fits Audi S4 18-25, S5 18-25 APR
SKU: A0CU CBK0012
Moderate — 2–4 hours
Description
Part #: CBK0012
Introducing the APR Catback Exhaust System for the Audi B9 S4 and S5
Features:
- Complete catalyst-back system including downpipes, extending from the factory catalyst back.
- Performance gains of 10 HP and 12 FT-LBS of torque delivered to all four wheels.
- Premium T304 stainless steel construction with TIG welding for strength and durability.
- Optimized flow through dual 2.5" downpipes, 2.75" midpipes, and a 3.5" midpipe.
- Mandrel-bent brushed piping paired with electropolished cast splitters for a refined finish.
- Precision brackets and slip clamps ensure accurate alignment and hassle-free installation.
- Includes an upgraded tunnel brace to accommodate the larger piping.
- Integrated Helmholtz resonator minimizes drone and enhances sound quality.
- Valve-controlled rear mufflers dynamically adjust sound based on driving style.
- Removable quad 3.5" motorsport-style polished tips with APR logo; optional styles available.
- Smooth transitions and straight-through components maximize performance by reducing restrictions.
- Strikes the perfect balance of power, sound, style, and quality for enthusiasts.
- Fully emissions compliant for worry-free operation.
Fits Audi S4 18-25, S5 18-25
MIA's Description
Fitment
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Specifications
| Brand | APR Tuning |
| Part Number | A0CU CBK0012 |
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Built for enthusiasts. Every order is backed by our 30 day return window on eligible items. Unused and uninstalled products may be returned with approved RMA and no restocking fees when received in new condition. Orders placed through the MOTORMIA app with a complete build qualify for our Fitment Guarantee — free return shipping if the part doesn’t fit your exact setup. The guarantee covers fit only; installation must follow manufacturer instructions, and we recommend a qualified shop for parts marked Difficulty 4–5.
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