To answer your question, NOTHING. The only draw backs are;
1- If you have to pass an emissions test, you may not.
2- You have to put up with the light being on.
Bottom line. If I had a '93 Chrysler Imperial with 174K on it and got 24 MPG, I wouldn't touch it. I would stroke it, and talk to it really, really nice every morning. Hope this helps.
Monday, March 16th, 2009 AT 8:19 PM