Milltek Large Bore Downpipe Hi-Flow Sports Cat | BMW 428i F32

Description

Milltek Large Bore Downpipe with integrated Hi-Flow Sports Catalyst for BMW 428i (F32). Direct factory fitment when paired with Milltek Cat-Back Exhaust System. Mandrel-bent T304L stainless steel construction with CNC-formed catalyst housing delivers increased flow over OEM restrictive units. Larger diameter core expands exhaust gas velocity and reduces backpressure, unlocking additional power and torque. Hi-Flow catalyst maintains street-legal emissions compliance while allowing full acoustic character expression. Stage 2 ECU remap required to extract peak performance and recalibrate fuel delivery. Fitment: • BMW 428i F32 (2014-2016) • Requires Milltek Cat-Back System for complete fitment • Uses OEM exhaust hangers — no modification required • Stage 2 tune mandatory Hand-finished welds and TIG construction throughout. This downpipe unlocks the full potential of your F32 when combined with proper engine management. Designed and manufactured in the UK with 40+ years of performance exhaust heritage. Tested at the Nurburgring.

Fits 3 vehicles including:

• 2014 BMW 4 Series— F32 428i Coupe (Automatic Gearbox, without Tow Bar, None xDrive & N20 Engine Only) > 2014 to 2016 / F32 428i Coupe (Manual Gearbox, without Tow Bar, None xDrive & N20 Engine Only) > 2014 to 2016
• 2015 BMW 4 Series— F32 428i Coupe (Automatic Gearbox, without Tow Bar, None xDrive & N20 Engine Only) > 2014 to 2016 / F32 428i Coupe (Manual Gearbox, without Tow Bar, None xDrive & N20 Engine Only) > 2014 to 2016
• 2016 BMW 4 Series— F32 428i Coupe (Automatic Gearbox, without Tow Bar, None xDrive & N20 Engine Only) > 2014 to 2016 / F32 428i Coupe (Manual Gearbox, without Tow Bar, None xDrive & N20 Engine Only) > 2014 to 2016