The Honda Civic 88-00 Straight High Flow Test Pipe test pipe is a metal straight pipe with a polish finish that replaces your catalytic converter. Once installed your exhaust system will sound louder and gain HP on the high end. (Warning: Test-pipes are for off-road use only and are not intended for highway use. O2 Simulators may be required if a CEL is triggered. Installing a test pipe will lead to failure of emissions.)