Catless downpipes eliminate the restrictive OEM converters on the stock downpipes allowing the exhaust to flow more freely, increasing power and torque. Because higher boost levels generate more heat, the Boost Monkey 335xi catless downpipes allows your AWD N54 to run boost settings of Stage 2 tunes and beyond.
The Boost Monkey 335xi catless downpipes are designed with 3" stainless steel construction to optimize exhaust flow off the turbochargers and reduce to 2.5" to match up perfectly to the OEM midpipes. Our 335xi downpipes are designed specifically to fit your AWD N54 platform.
Each downpipe has two O2 sensor bungs so the factory BMW O2 sensors can be remounted allowing the ECU to continue to monitor the air/fuel mixture via the exhaust. Because these downpipes are a catless design, an ECU tune or CEL fix will be needed to avoid a CEL from displaying on instrument panel.
Gain 25whp + 37wtq
Improved Exhaust Sound
304 Stainless Steel
FITMENT GUIDE - AWD VEHICLES ONLY
2007-2010 BMW 335xi Coupe/Sedan/Convertible (N54 Only)