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Home >> Suzuki >> 2002 >> XL-7 Plus >> Repair and Diagnosis >> External Pages >> Different car >> Section 7 (Engine Controls - Self-Diagnostics - 2.2L) >> Diagnostic Tests >> DTC P0420: Catalytic CONVERTOR System Efficiency Below Threshold >> Diagnostic Procedure
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Diagnostic Procedure

WARNING: This page is about a different car, the 2002 Isuzu Rodeo Sport and 2002 Isuzu Rodeo. However, it is still accessible from the selected car via links, so may be relevant.
  1. Perform ON-BOARD DIAGNOSTIC II SYSTEM CHECK  under SELF-DIAGNOSTIC SYSTEM. After performing OBD-II system check, go to next step.
  2. If any other DTCs other than P0420 or P0430 are set, diagnose affected DTCs before proceeding. See DIAGNOSTIC TROUBLE CODE DEFINITIONS  . If no other DTCs are set, go to next step.
  3. Ensure Three Way Catalytic Converter (TWC) is an original equipment part. Check TWC for dents, holes or discoloration caused by excessive heat. Ensure rattle caused by internal catalyst damage is not present. If a problem is found, repair as necessary and go to step  6 . If no problems are found, go to next step.
  4. Check exhaust system for leaks, damage, loose or missing hardware. If a problem is found, repair as necessary and go to step  7 . If no problems are found, go to next step.
  5. Ensure Bank 1 HO2S-2 is securely installed and that harness is not damaged or contacting exhaust. If a problem is found, repair as necessary and go to step  7 . If no problems are found, go to next step.
  6. Replace suspect TWC. Check for possible engine misfire or engine mechanical problems which may cause catalytic converter damage. After repair, go to next step.
  7. Read and record FAILURE RECORDS data for DTC P0420 or DTC P0430. Clear DTCs. Start engine and allow coolant temperature to reach 140°F (60°C). Run engine while monitoring scan tool maintaining MAF sensor range at 8-50 grams/sec., for at least 2 minutes. Using scan tool, monitor TWC MONITOR TEST COUNTER while operating vehicle within CODE ENABLE CRITERIA  . If scan tool displays DTC P0420 PASSED THIS IGNITION, repair is complete. If scan tool does not display DTC P0420 PASSED THIS IGNITION, go to DIAGNOSTIC AIDS  . After repair is complete, see VERIFYING VEHICLE REPAIR  under SELF-DIAGNOSTIC SYSTEM. After repair, if driveability symptom still exists, repair by symptom. See TROUBLE SHOOTING - NO CODES article.
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