Active Autowerke Exhaust Section 1 With 100 Cell Hi Flow Catalysts For Bmw E46 M3

BMW PERFORMANCE PARTS: ACTIVE AUTOWERKE  EXHAUST SECTION 1 WITH 100 CELL HI FLOW CATALYSTS for BMW E46 M3 Product Features: Designed and recommended for Off Road Use Pair of 100 CELL Hi Flow metallic exhaust catalysts included No unburnt fuel like smell NO RASP like sound Brushed Finish for that industrial appeal Constructed from 100% 304 stainless steel Utilizes factory mounting points for easy bolt-on install Two year warranty with Free Tech support Combine the Active Autowerke Exhaust SECTION 1 with a pair of Hi Flow 100 cell metallic catalysts and you have part of a winning combination for your BMW E46 M3. DESIGN AND CONCEPT: The Active Autowerke Exhaust SECTION 1 only comes into play if the E46 M3 already has a performance header already installed.  One will experience a high smell of unburnt fuel. (due to the open exhaust w/o any catalysts) and development of a RASPY like sound of which the BMW S54 engine is notorious for with the BMW Stock Section 1 when equipped. This raspy like sound is a matter of engine sound harmonics at a specific RPM range, a sort of resonance that is very loud and noticeable when the engine is revving at or above 4,000 rpm. With the Active Autowerke Exhaust SECTION 1 installed, the BMW performance gains are about the same as running the factory section 1. However, that's impressive considering the exhaust flow is also being filtered while running through a pair of 100 cell catalysts. The power and performance is still there. Gone is the smell of unburnt fuel. A BIG advantage. Gone is the RASP like sound. Another BIG advantage. Fitment: BMW E46 M3