Diagnostic Aids: Notes
WARNING: This page is about a different car, the 1995 Chevrolet Corvette. However, it is still accessible from the selected car via links, so may be relevant.
If other codes of lower number are set with code, use those charts first. Malfunction in MAP or TPS sensor circuits can cause a rich exhaust code to set. If other codes are not set, rich exhaust is most likely caused by: