Evolve Cat Delete/Test Pipes - BMW E90 | E92 | E93 M3NOT ROAD LEGAL It is well known that the Primary cats are a major restriction point on the E9X M3. There are a number of solutions on the market including a full X Pipe which removes the primary cats or Primary Cat Delete Test Pipes. Primary Cat Delete Test Pipes are designed for those who do not want to go the full X Pipe route and are happy to modify their existing X Pipe. It is the most cost effective way of releasing power from this car. Our