Audi A4 B5 Downpipes – Catted & Decat Performance Exhaust Upgrades

Audi A4 B5 Downpipes – Unlock Classic Turbocharged Performance

The Audi A4 B5, produced from 1994 to 2001, marked the first generation of Audi’s premium mid-size sedan and remains a favorite among tuning enthusiasts. Known for its robust build quality, quattro all-wheel-drive systems and tunable turbo engines, the B5 is a legend in the VAG tuning world. However, the factory exhaust system, especially the downpipe, restricts airflow and limits potential power gains. Installing a performance Audi A4 B5 downpipe is one of the most effective upgrades to unleash more horsepower, faster turbo spool and a sportier exhaust tone.

Why Upgrade to a Performance Audi A4 B5 Downpipe?

The OEM downpipe on the Audi A4 B5 is designed for emissions compliance and quiet operation, which creates exhaust restrictions that hinder performance. A performance downpipe solves this by offering:

• Increased horsepower and torque – optimized exhaust flow reduces backpressure and improves turbocharger efficiency.
• Faster turbo spool – enjoy reduced lag and stronger acceleration.
• Enhanced exhaust tone – catted downpipes give a refined, sporty sound, while decat downpipes deliver an aggressive, motorsport-inspired roar.
• Lower exhaust gas temperatures – better thermal management protects your engine and turbo under heavy loads.
• Essential for ECU tuning – critical for Stage 1, Stage 2 and big-turbo remaps.

Types of Audi A4 B5 Downpipes

We offer a wide selection of Audi A4 B5 downpipes designed for petrol and diesel models, from stock refresh builds to high-power performance setups:

Catted Audi A4 B5 Downpipes

Catted downpipes feature a high-flow sports catalytic converter that balances performance with emissions compliance. Perfect for daily-driven B5 models where MOT testing and road legality are important.

Decat Audi A4 B5 Downpipes

Decat downpipes remove the catalytic converter entirely for maximum exhaust flow, quicker spool and higher peak power. Ideal for track builds, off-road setups or regions without emissions testing.

Stainless Steel & Titanium Audi A4 B5 Downpipes

Material choice is key to long-term performance:

• Stainless steel downpipes – corrosion-resistant, durable and ideal for most builds.
• Titanium downpipes – ultra-lightweight, superior thermal control and a premium motorsport finish.

Engine Compatibility

Our Audi A4 B5 downpipes are compatible with a wide range of engines, including:

• Audi A4 B5 1.8T Downpipes – optimized for both 150HP and 180HP variants.
• Audi A4 B5 2.4 / 2.8 V6 Downpipes – designed for smooth-flowing exhaust performance on naturally aspirated setups.
• Audi A4 B5 1.9 TDI Downpipes – engineered for torque gains and improved efficiency on diesel variants.
• Audi S4 B5 Downpipes – high-performance solutions for the iconic 2.7T twin-turbo quattro models.

Performance Gains with Audi A4 B5 Downpipes

Installing a performance Audi A4 B5 downpipe provides instant results. Typical gains include:

• +12–20 HP with the downpipe alone.
• +25–45 HP when paired with Stage 1 or Stage 2 ECU remapping.
• Improved torque delivery for stronger mid-range performance.
• Sharper throttle response and reduced turbo lag.

Choosing the Right Diameter

Exhaust pipe diameter plays a vital role in achieving performance goals. Popular sizes for Audi A4 B5 downpipes include:

• 2.5-inch downpipes – perfect for Stage 1 builds and lightly modified setups.
• 3-inch downpipes – ideal for Stage 2, hybrid turbos and high-boost configurations.

All our downpipes are designed for direct bolt-on installation, ensuring seamless integration with OEM exhaust systems.

Build Quality & Engineering

Our performance Audi A4 B5 downpipes are engineered for maximum durability and efficiency. Features include:

• Mandrel-bent tubing for unrestricted exhaust flow.
• High-grade stainless steel or lightweight titanium construction.
• Precision TIG welding for strength and leak-free performance.
• OEM-style flanges and fittings for perfect fitment.

Tuning Potential

Pairing a performance Audi A4 B5 downpipe with ECU remapping unlocks the full potential of your engine:

• Significant horsepower and torque improvements.
• Optimized boost control and fuel mapping.
• Sharper throttle response and enhanced drivability.
• Customizable exhaust sound depending on catted or decat setup.

Daily Driving vs Track Builds

For street-driven cars, catted downpipes provide the best balance between performance and compliance. For track-focused builds, decat downpipes deliver maximum flow, peak power and an aggressive motorsport sound.

Conclusion

Upgrading to a performance Audi A4 B5 downpipe is one of the best modifications you can make for more power, improved turbo response and a sportier exhaust tone. Whether you choose a catted downpipe for everyday usability or a decat downpipe for maximum performance, our selection of Audi A4 B5 downpipes ensures premium quality, perfect fitment and proven gains. Unlock your B5’s full tuning potential today.