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Catalytic Converter System Acura ZDX I

Exhaust 4 illustrations ~1033 words

Scheme 1

Scheme 1: Component Location Index
Scheme 1: Component Location Index

DTC P0420: Rear Bank Catalyst System Efficiency Below Threshold (Bank 1); DTC P0430: Front Bank Catalyst System Efficiency Below Threshold (Bank 2)

Note. Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information (see GENERAL TROUBLESHOOTING INFORMATION ). If some of the DTCs listed below are stored at the same time as DTC P0420 and/or P0430*, troubleshoot those DTCs first, then recheck for DTC P0420 and/or P0430*.

P0137, P0138, P0157*, P0158*, P2270, P2272*: Secondary HO2S (Sensor 2)

P0141, P0161*: Secondary HO2S (Sensor 2) heater

P0300: Random misfire detected

P0301-P0306: No. 1, No. 2, No. 3, No. 4, No. 5, or No. 6 cylinder misfire detected

  1. Poor quality fuel can cause these DTCs.
  2. Information marked with an asterisk (*) applies to the front bank (Bank 2).
  1. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.
  2. Clear the DTC with the HDS.
  3. Start the engine. Hold the engine speed at 3, 000 rpm without load (in P or N) 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 Vehicle speed between 45-75 mph (72-120 km/h) for 5 minutes or more Vehicle speed between 55-75 mph (88-120 km/h) for 10 seconds, then decelerate (with the throttle fully closed). Repeat this three or more times. 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 and/or P0430* in the DTCs MENU with the HDS. Does the HDS indicate EXECUTING? YES -Go to step 6. NO -If the HDS indicates OUT OF CONDITION, go to step 4 and recheck. If the HDS indicates PASSED, intermittent failure, the system is OK at this time. If the HDS indicates FAILED, go to step 8 .
  6. Continue test driving until a result comes on.
  7. Monitor the OBD STATUS for DTC P0420 and/or P0430, in the DTCs MENU with the HDS. Does the HDS indicate FAILED? YES -Go to step 8. NO -If the HDS indicates PASSED, intermittent failure, the system is OK at this time. If the HDS indicates EXECUTING, keep driving until a result comes on. If the HDS indicates OUT OF CONDITION, go to step 4 and recheck.
  8. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
  9. Replace the WU-TWC: For DTC P0420, replace the rear WU-TWC (Bank 1) (see «REAR WU-TWC (Bank 1)»(/acura/zdx/i-2009-2013/remont/exhaust/#catalytic-converter-system) ). For DTC P0430, replace the front WU-TWC (Bank 2) (see «FRONT WU-TWC (Bank 2)»(/acura/zdx/i-2009-2013/remont/exhaust/#catalytic-converter-system) ).
  10. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.
  11. Reset the PCM with the HDS.
  12. Do the PCM idle learn procedure (see «PCM IDLE LEARN PROCEDURE»(/acura/zdx/i-2009-2013/remont/testing-diagnostics/#idle-control-system__pcm-idle-learn-procedure) ).
  13. Test-drive for about 10 minutes, continually changing the vehicle speed.
  14. Check the CATA MONITOR CONDITION B1 (B2)* in the DATA LIST with the HDS. Is the condition OK? YES -Go to step 15. NO -Go to step 13 and recheck.
  15. Test-drive under these conditions: Engine coolant temperature (ECT SENSOR 1) above 158°F(70°C) Transmission in D Vehicle speed between 55-75 mph (88-120 km/h) for 10 seconds, then decelerate (with the throttle fully closed). Repeat this three or more times. Maintain the vehicle speed at 55 mph (88 km/h) for 5 minutes or more with cruise control set.
  16. Continue test driving until a result comes on.
  17. Check for Pending or Confirmed DTCs with the HDS. Is DTC P0420 and/or P0430* indicated? YES -Check for fuel quality, then go to step 1 . NO -Go to step 18.
  18. Monitor the OBD STATUS for DTC P0420 and/or P0430* in the DTCs MENU with the HDS. Does the HDS indicate PASSED? YES -Troubleshooting is complete. If any other Pending or Confirmed DTCs were indicated in step 17 , go to the indicated «DTCS TROUBLESHOOTING»(/acura/zdx/i-2009-2013/remont/exhaust/#catalytic-converter-system) . NO -If the HDS indicates FAILED, check the fuel quality, then go to step 1 . If the HDS indicates EXECUTING, keep driving until a result comes on. If the HDS indicates OUT OF CONDITION, go to step 15 .

Scheme 2

Scheme 2: FRONT WU-TWC (Bank 2)
Scheme 2: FRONT WU-TWC (Bank 2)
  1. Remove the No. 2 the ignition coil (A) and the ignition coil heat insulator (B).
  2. Remove the front A/F sensor (Sensor 1) (see «A/F SENSOR REPLACEMENT»(/acura/zdx/i-2009-2013/remont/testing-diagnostics/#pgm-fi-system__af-sensor-replacement) ) and front secondary HO2S (Sensor 2) (see «SECONDARY HO2S REPLACEMENT»(/acura/zdx/i-2009-2013/remont/testing-diagnostics/#pgm-fi-system__secondary-ho2s-replacement) ).
  3. Remove exhaust pipe A (see «EXHAUST PIPE AND MUFFLER REPLACEMENT»(/acura/zdx/i-2009-2013/remont/mechanical/#intake-manifold-and-exhaust-system__exhaust-pipe-and-muffler-replacement) ).
  4. Remove the EGR pipe (see «EGR VALVE REPLACEMENT»(/acura/zdx/i-2009-2013/remont/auxiliary-emission-control-systems/#egr-system) ).
  5. Remove the A/C condenser fan assembly (see «FAN, FAN MOTOR, AND SHROUD REMOVAL AND INSTALLATION»(/acura/zdx/i-2009-2013/remont/cooling-fan/#engine-cooling-system) ) and the radiator upper bracket/cushion (see step 11 under «RADIATOR REPLACEMENT»(/acura/zdx/i-2009-2013/remont/cooling-fan/#engine-cooling-system) ).
  6. Remove the front WU-TWC bracket (C), then carefully remove the front WU-TWC (D).
  7. Remove the converter covers (E).
  8. Carefully install the front WU-TWC with a new gasket (F) and new self-locking nuts (G). Tighten the nuts in a crisscross pattern in two or three steps.
  9. Install the parts in the reverse order of removal.

Scheme 3

Scheme 3: REAR WU-TWC (Bank 1)
Scheme 3: REAR WU-TWC (Bank 1)
  1. Remove the rear A/F sensor (Sensor 1) (see «A/F SENSOR REPLACEMENT»(/acura/zdx/i-2009-2013/remont/testing-diagnostics/#pgm-fi-system__af-sensor-replacement) ) and rear secondary HO2S (Sensor 2) (see «SECONDARY HO2S REPLACEMENT»(/acura/zdx/i-2009-2013/remont/testing-diagnostics/#pgm-fi-system__secondary-ho2s-replacement) ).
  2. Remove exhaust pipe A (see «EXHAUST PIPE AND MUFFLER REPLACEMENT»(/acura/zdx/i-2009-2013/remont/mechanical/#intake-manifold-and-exhaust-system__exhaust-pipe-and-muffler-replacement) ).
  3. Remove the intermediate shaft (see «INTERMEDIATE SHAFT REMOVAL»(/acura/zdx/i-2009-2013/remont/axle-shafts/#drivelineaxle) ).
  4. Remove the rear WU-TWC bracket (A), then carefully remove the rear WU-TWC (B).
  5. Remove the converter covers (C).
  6. Carefully install the rear WU-TWC with a new gasket (D) and new self-locking nuts (E). Tighten the nuts in a crisscross pattern in two or three steps.
  7. Install the parts in the reverse order of removal.

Scheme 4

Scheme 4: Under-Floor TWC Removal/Installation
Scheme 4: Under-Floor TWC Removal/Installation
  1. Raise the vehicle on a lift.
  2. Remove the exhaust pipe hanger (A).
  3. Remove the under-floor TWC (B).
  4. Remove the converter covers (C).
  5. Install the parts in the reverse order of removal with new gaskets (D) and new self-locking nuts (E and F).