Milltek Sport Active Exhaust Valve Controller Module | BMW G8X M3/M4

Take absolute acoustic control over your S58 powerplant with the Milltek Sport Active Exhaust Valve Controller Module. The stock BMW ECU restricts valve angles, keeping them heavily muffled even in Sport+ mode. The Milltek plug-and-play module bypasses these computer constraints entirely, allowing you to instantly force your exhaust valves 100% wide open at any RPM or speed. Command a massive, raw cold start and deep low-end rumble on demand, or quickly switch back to stock logic for neighbor-friendly operations. Easy installation with zero splicing or permanent vehicle modification required.