Diagnostic Aids
WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 1997 GMC Yukon, 1997 GMC Suburban, 1997 GMC Pickup, 1997 GMC Cab & Chassis, and 1997 Chevrolet Tahoe. However, it is still accessible from the selected car via links, so may be relevant.
Difficulty running OBD-II status DTC P0430 test may be encountered in areas where test conditions cannot be easily maintained, especially in urban areas. To minimize driving time required to complete test, catalyst can be warmed up in service bay previous to drive cycle. Engine can also be warmed up in service bay.
Using scan tool, monitor MAP sensor; HO2S bank 2, sensor 1 and HO2S bank 2, sensor 2 displays with gear selector in Park or Neutral with engine above idle. Compare HO2S activity (amplitude and frequency) to each other during a 30 second time period. If HO2S 2 activity is nearly as great as HO2S 1 activity, a problem is present. If less activity is indicated, TWC system is properly functioning.