The Active Autowerke BMW E46 M3 Header is designed to increase exhaust flow without losing power which can sometimes be a tricky proposition.
These headers are developed to create optimum flow and eliminate restriction that rob much desired horsepower. Following the famed BMW E46 M3 CSL headers, each individual header runner of the Active Autowerke header is cut to a matched equal length to ensure a consistent exhaust scavenging (tolerance in lengths vary by bends to a mean average of 10-20mm).
The four oxygen sensors are temporarily removed to install the exhaust headers. Sometimes the exact placement of these sensors are not correct, resulting in a **CHECK ENGINE ** light. Active Autowerke has created a simple, efficient schematic diagram showing the exact placement with proper connections needed for a seamless re-install.