Hey guys this is my first post I just purchased a 2003 Mach 1 and have a question about it. When I start up the car white smoke shoots out of the exhaust of the driver's side. The engine light came on and I got a code for it, P0420. The explanation: The oxygen sensors monitor the Catalyic Converters ability to store oxygen. Has anyone ever gotten this code and what did you do to fix it? Thanks.