2001 Kia Rio: The check engine light has been on for a while now, and I have the P0420 Diagnostic code coming up on my scan gauge. The dealer has replaced the front O2 sensor, the MAF, and the catalytic converter. Could the problem continue due to a faulty rear O2 sensor? This problem has both me and my service technicians baffled.
Sunday, July 30th, 2006 AT 8:52 AM