I have a 95 civic sedan and i just ordered a test pipe. I've heard many things about a test pipe good and bad. First, I wasnt sure if i was suppose to get the test pipe with the bung for the 02 sensor or w/o. Which one should of i've got. Second, would a test pipe make my check engine light go one. If so, how would i stop it from going on. Third, is it true that your car stinks if u put a test pipe on? If anyone can help that would be great.