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Catalytic Converter System Acura RSX I

Auxiliary Emission Control Systems ~721 words

DTC Troubleshooting

DTCDescription
DTC P0420Catalyst System Efficiency Below Threshold (2002-2004 models)
DTC P0420Catalyst System Efficiency Below Threshold (2005-2006 models)

DTC INDEX

DTC P0420: Catalyst System Efficiency Below Threshold (2002-2004 models)

Note. If some of the DTCs listed below are stored at the same time as DTC P0420, troubleshoot those DTCs first, then recheck for DTC P0420.

P0137, P0138: Secondary HO2S (Sensor 2)

P0141: Secondary HO2S (Sensor 2) heater

  1. Reset the ECM/PCM (see «ECM/PCM RESET (2002-2004 MODELS)»(/acura/rsx/i-2001-2004/remont/auxiliary-emission-control-systems/#fuel-system-emissions-systems__ecmpcm-reset-2002-2004-models) ).
  2. Start the engine. Hold the engine speed at 3,000 RPM without load (in Park or neutral) until the radiator fan comes on.
  3. Test-drive at 50-55 mph (80-88 km/h) for about 2 minutes. Then decelerate for at least 4 seconds with the throttle completely closed. Then accelerate to 55 mph (88 km/h), and try to hold the speed until the HDS indicates FAIL or PASS as the TWC test result. Is the test result FAIL? YES - Check the three way catalytic converter (TWC). If necessary, replace the TWC. NO - Intermittent failure, system is OK at this time.

DTC P0420: Catalyst System Efficiency Below Threshold (2005-2006 models)

Note. If some of the DTCs listed below are stored at the same time as DTC P0420, troubleshoot those DTCs first, then recheck for DTC P0420. P0137, P0138: Secondary HO2S (Sensor 2) P0141: Secondary HO2S (Sensor 2) heater Poor quality fuel may cause this DTC.

  1. Turn the ignition switch ON (II).
  2. Clear the DTC with the HDS.
  3. Start the engine. Hold the engine speed at 3,000 RPM without load (in Park or neutral) until the radiator fan comes on, then let it idle.
  4. Test-drive under these conditions: Engine coolant temperature above 158°F (70°C) A/T in D position (M/T in 5th gear) Vehicle speed between 45 mph (72 km/h) and 75 mph (120 km/h) for 5 minutes or more Maintain a vehicle speed above 25 mph (40 km/h) for 5 minutes with cruise control set
  5. Monitor the OBD STATUS for DTC P0420 in the DTCs MENU with the HDS. Does the screen indicate EXECUTING? YES - Go to step 6. NO - Go to step 4 and recheck.
  6. Continue test driving until a result comes on.
  7. Monitor the OBD STATUS for DTC P0420 in the DTCs MENU with the HDS. Does the screen indicate FAILED? YES - Go to step 8. NO - If the screen indicates PASSED, intermittent failure, system is OK at this time. If the screen indicates EXECUTING, keep driving until a result comes on. If the screen indicates OUT OF CONDITION, go to step 4 and recheck.
  8. Turn the ignition switch OFF.
  9. Replace the three way catalytic converter (TWC) (see «EXHAUST PIPE AND MUFFLER REPLACEMENT»(/acura/rsx/i-2001-2004/remont/exhaust/#intake-manifold-and-exhaust-system__exhaust-pipe-and-muffler-replacement) ).
  10. Turn the ignition switch ON (II).
  11. Reset the ECM/PCM with the HDS.
  12. Do the ECM/PCM idle learn procedure (see «ECM/PCM IDLE LEARN PROCEDURE»(/acura/rsx/i-2001-2004/remont/testing-diagnostics/#idle-control-system) ).
  13. Start the engine. Hold the engine speed at 3,000 RPM without load (in Park or neutral) until the radiator fan comes on, then let it idle.
  14. Test-drive for about 10 minutes, varying the vehicle speed.
  15. Check the CAT MONITOR CONDITION in the DATA LIST with the HDS. Is the temperature OK? YES - Go to step 16. NO - Go to step 13 and recheck.
  16. Test-drive under these conditions: Engine coolant temperature above 158°F (70°C) A/T in D position (M/T in 5th gear) Vehicle speed between 45 mph (72 km/h) and 75 mph (120 km/h) for 5 minutes or more Maintain a vehicle speed above 25 mph (40 km/h) for 5 minutes with cruise control set
  17. Monitor the OBD STATUS for DTC P0420 in the DTCs MENU with the HDS. Does the screen indicate EXECUTING? YES - Go to step 18. NO - Go to step 16 and recheck.
  18. Continue test driving until a result comes on.
  19. Check for Temporary DTCs or DTCs with the HDS. Are any Temporary DTCs or DTCs indicated? YES - Go to the indicated DTC's troubleshooting. NO - Go to step 20.
  20. Monitor the OBD STATUS for DTC P0420 in the DTCs MENU with the HDS. Does the screen indicate PASSED? YES - Troubleshooting is complete. NO - If the screen indicates FAILED, check the fuel quality. If the screen indicates EXECUTING, keep driving until a result comes on. If the screen indicates OUT OF CONDITION, go to step 13 and recheck.

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