MR-SSDP-NS0725 STAINLESS STEEL Downpipe 4-1 SENTRA 07-12 2.5LRacing Down pipe will replace your OEM exhaust piping with all of its restrictive bends, so the inner diameter of pipe will increase. The result: freeing up high end horsepower and mid range torque with increase in exhaust flow and reduced turbulence in the system. Notes: Race Only product that is not to be used on vehicles that are operated on public streets, roads or highways