IRL - EPA Compliant 400 CEL Downpipes - BMW G8X M2/M3/M4

Upgrade the performance and sound of BMW's S58 twin-turbocharged inline-six with the IRL Performance 400-Cell High-Flow Catted Downpipes. Engineered to reduce exhaust restriction while retaining high-flow catalytic converters, these downpipes offer an excellent balance of performance, exhaust sound, and everyday drivability.

Featuring premium 400-cell high-flow catalytic converters, the IRL downpipes are designed to improve exhaust gas flow and reduce backpressure compared to the factory system. The improved flow characteristics can support faster turbocharger response, stronger power delivery, and a more engaging driving experience, particularly when combined with additional performance upgrades.

Constructed entirely from T304 stainless steel, each downpipe features precision mandrel-bent tubing, TIG-welded joints, and OEM-style oxygen sensor locations for straightforward installation using factory mounting points.

Features

• 400-Cell High-Flow Catalytic Converters: Designed to reduce exhaust restriction while retaining catalytic converter functionality
• Improved Exhaust Flow: Reduced backpressure supports improved turbocharger efficiency and performance potential
• Enhanced S58 Exhaust Note: Produces a deeper, more aggressive exhaust tone with increased turbocharger acoustics
• T304 Stainless Steel Construction: Premium corrosion-resistant materials provide durability under demanding operating conditions
• Mandrel-Bent Tubing: Smooth internal transitions promote efficient exhaust flow
• TIG-Welded Construction: Precision fabrication provides strength and long-term reliability
• Direct Bolt-On Fitment: Designed to utilize factory mounting locations and oxygen sensor positions
• Street-Oriented Sound Characteristics: Designed to complement the factory exhaust or aftermarket midpipe and cat-back configurations

Performance & Sound
The IRL 400-Cell Downpipes enhance the S58's distinctive exhaust character without requiring a complete exhaust system replacement. Expect a deeper exhaust note, more pronounced turbocharger sounds, and a more responsive feel under acceleration.

When combined with an aftermarket midpipe or cat-back exhaust, the system can deliver an even more aggressive, motorsport-inspired sound.

Manufacturer-Advertised No-CEL Design
IRL advertises these downpipes as designed to operate without triggering a CEL under supported vehicle configurations.

2026 Model Year Notice: Due to changes in BMW engine-management software and emissions monitoring, certain 2026 vehicles may trigger a check engine light following installation. IRL is continuing to evaluate compatibility with updated software versions.

Warranty
2-Year Catalyst Warranty provided by IRL, subject to manufacturer warranty terms.

Vehicles Supported
BMW G87 M2 
BMW G8X M3/M4, including Competition