Mike's Workshop Manuals: Service manuals for every vehicle
Home >> Chevrolet >> 2006 >> Uplander Base >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - 3.5L - DTC P0220 To DTC P0455 >> DTC P0420 >> Conditions for Setting the DTC

Conditions for Setting the DTC

The PCM determines that the efficiency of the catalyst has degraded below a calibrated threshold. This diagnostic may conclude in as few as one test attempt. However, this diagnostic may require as many as 18 test attempts, which would require at least 3 drive cycles. Each test attempt concludes within 2 minutes.