LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Saturn >> 2007 >> Relay 3.9 W >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls And Fuel - DTC P0010 To DTC P0420 >> DTC P0420 >> Repair Verification
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Repair Verification

  1. Clear the DTCs.
  2. Allow the engine coolant temperature to reach 70°C (156°F).
    • Place the gear selector in Park, Neutral for manual.
    • Set the parking brake.
  3. Press and hold the service brake.
  4. Run the engine for 6 minutes at 2,500 RPM.
  5. Allow engine speed to return to idle speed, then place gear selector into Drive, or apply clutch pedal for manual.
  6. After 2 minutes, verify that DTC P0420 has passed or failed this ignition cycle.
    • If not passed or failed this ignition cycle, the test aborted resulting in an inconclusive test result. The above test may need to be repeated up to 5 more times during this drive cycle. The first test should be run after the initial warm up period of 6 minutes. Between subsequent tests maintain 2,500 RPM for 2 minutes.
  7. If 6 tests have been attempted and the DTC has not run or passed during this key cycle, turn the key to OFF for 30 seconds, then run the procedure a second time.
scientia non olet · About LEMON Manuals