Catalytic Converter System Acura RDX I

Scheme 80

DTC P0420: Catalyst System Efficiency Below Threshold

Note. Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information (see GENERAL TROUBLESHOOTING INFORMATION ). 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 (ECT SENSOR 1) above 158°F (70°C) Transmission in D position Vehicle speed between 45-75 mph (72 - 120 km/h) for 5 minutes or more with cruise control set Maintain the vehicle speed at 55 mph (88 km/h) for 5 minutes or more 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 -If the screen indicates OUT OF CONDITION, go to step 4 and recheck. If the screen indicates PASSED, intermittent failure, the system is OK at this time. If the screen indicates FAILED, go to step 8 .
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, the 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 to LOCK (0) .
9. Replace the WU-TWC (see «WARM UP TWC REMOVAL/INSTALLATION»(/acura/rdx/i-2006-2009/remont/auxiliary-emission-control-systems/#catalytic-converter-system) ).
10. Turn the ignition switch ON (II).
11. Reset the PCM with the HDS.
12. Do the PCM idle learn procedure (see «PCM IDLE LEARN PROCEDURE»(/acura/rdx/i-2006-2009/remont/engine-control-systems/#idle-control-system__pcm-idle-learn-procedure) ).
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 CATA 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 (ECT SENSOR 1) above 158°F (70°C) Transmission in D position Vehicle speed at 55 mph (88 km/h) for 5 minutes or more 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 DTCs 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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Scheme 90

1. Remove the charge air cooler cover.
2. Remove the charge air cooler cover bracket (A).
3. Remove the power steering feed hose stay (B), then move the hose (C) in the direction of the arrow.
4. Remove the bolts (A), then remove the turbocharger cover (B).
5. Remove the A/F sensor (see «A/F SENSOR REPLACEMENT»(/acura/rdx/i-2006-2009/remont/testing-diagnostics/#pgm-fi-system__af-sensor-replacement) ).
6. Remove the water hose upper cover (A). *: This view is from the rear of the engine compartment.
7. Remove the bolts (B) and nut (C).
8. Raise the vehicle all the way up on a lift.
9. Remove the under-floor TWC (see «UNDER-FLOOR TWC REMOVAL/INSTALLATION»(/acura/rdx/i-2006-2009/remont/auxiliary-emission-control-systems/#catalytic-converter-system) ).
10. Remove the secondary HO2S (see «A/F SENSOR REPLACEMENT»(/acura/rdx/i-2006-2009/remont/testing-diagnostics/#pgm-fi-system__af-sensor-replacement) ).
11. Remove the splash shield (see «FRONT SPLASH SHIELD REPLACEMENT»(/acura/rdx/i-2006-2009/remont/exterior-body-panels/#fenderwell__front-splash-shield-replacement) ).
12. Remove the intermediate shaft (see «INTERMEDIATE SHAFT REMOVAL»(/acura/rdx/i-2006-2009/remont/axle-shafts/#drivelineaxle) ).
13. Remove the P/S heat shield (see step 22 on page 17-32).
14. Disconnect the engine oil pressure switch connector (A), the right front wheel sensor connector (B), and the CKP sensor connector (C), then remove harness clamp (D).
15. Remove the water hose lower cover (E).
16. Remove the torque rod mounting bolts (A) from the oil pan.
17. Remove the WU-TWC bracket (A), then remove the WU-TWC (B) and gasket (C) from the turbocharger.
18. Lower the WU-TWC.
19. Turn the under-floor TWC side of the WU-TWC upward as shown.
20. After the turbocharger side of the WU-TWC came out, turn the under-floor TWC side of the WU-TWC downward, and take it out by turning it.
21. Remove the converter cover (A).
22. Install the parts in the reverse order of removal with new gaskets (turbocharger side and under-floor TWC side). Also, replace the bolts and nut that attach the WU-TWC to the turbocharger.
23. Refill the ATF (see «ATF REPLACEMENT»(/acura/rdx/i-2006-2009/remont/automatic-trans/#automatic-transmission) ).

Scheme 91

1. Remove the under-floor TWC (A).
2. Remove the converter cover (B).
3. Install the parts in the reverse order of removal with new gaskets (C).

See also:
• GENERAL TROUBLESHOOTING INFORMATION
• PCM IDLE LEARN PROCEDURE
• A/F SENSOR REPLACEMENT
• FRONT SPLASH SHIELD REPLACEMENT
• INTERMEDIATE SHAFT REMOVAL
• ATF REPLACEMENT
• WARM UP TWC REMOVAL/INSTALLATION