Conditions For Running Test

WARNING: This page is about a different car, the 2003 Pontiac Grand Prix, 2003 Chevrolet Malibu, and 2003 Buick Century. However, it is still accessible from the selected car via links, so may be relevant.

Meet the conditions for engine warm up. Use the scan tool catalyst data list to verify the following:

DTCs P0101, P0102, P0103, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0121, P0122, P0123, P0130, P0131, P0132, P0133, P0134, P0135, P0137, P0138, P0140, P0141, P0171, P0172, P0201-P0206, P0300, P0325, P0327, P0336, P0341, P0401, P0403, P0404, P0405, P0410, P0412, P0418, P0440, P0442, P0443, P0446, P0449, P0502, P0503, P0506, P0507, P1133, P1134, P1336, P1351, P1352, P1361, P1374 or P1441 are not set.
The engine has been running more than 10 minutes.
The Engine Coolant Temperature (ECT) is above 158°F (70°C) and below 255°F (124°C).
The BARO sensor parameter is more than 75 kPa.
The vehicle is in a closed loop operation.
The Intake Air Temperature (IAT) is above -4°F (-20°C), and is less than 212°F (100°C).
The battery voltage above 10.7 volts.

Warm the catalyst:

Fully open the hood.
The vehicle is in Park (A/T) or in Neutral (M/T).
Set the parking brake.
Press and hold the service brake.
Each time the engine is started the diagnostic can run up to 18 times. After the 10 minute run time and before the diagnostic runs the first time, the engine must run an additional 5 minutes between 1500-2500 RPM. Any additional tests on the same key cycle, the engine speed must be between 1500-2500 RPM for 1 minute.
To activate the diagnostic, return to idle and put the vehicle in drive (depress the clutch for manual).

Test the catalyst.

Transmission is in Drive (A/T) or Neutral (M/T with clutch depressed).
Verify if DTC P0420 has passed or failed this key cycle using the scan tool.