Exhaust Mid Race Pipe for Honda Civic (2001-2005) 1.7L EngineHigh Flow Exhaust Mid Race Pipe for 2001 2005 Honda Civic (D17 EM2) What it Does: Replaces the restrictive factory mid section with a straight through 2. 25 inch mandrel bent T 304 stainless steel pipe to maximize exhaust gas velocity and reduce parasitic backpressure on 1. 7L D series engines. The Stock Civic Bottleneck The OEM exhaust piping on the 7th Generation Civic is engineered primarily for cabin silence and mass production cost savings rather