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Home >> Suzuki >> 2001 >> Grand Vitara JLS, Standard >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Self-Diagnostics >> Diagnostic Tests >> DTC P0420: Left Bank Catalyst System Low Efficiency, Or DTC P0430: Right Bank Catalyst System Low Efficiency >> Diagnosis & Repair Procedure
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Diagnosis & Repair Procedure

  1. Check for DTCs P0101, P0102, P0103, P0111, P0112, P0113, P0116, P0117, P0118, P0131, P0132, P0133, P0134, P0135, P0136, P0141, P0335, P0461, P0446, P0500, P1450 and P1451. See RETRIEVING DIAGNOSTIC TROUBLE CODES  under SELF-DIAGNOSTIC SYSTEM. If DTCs are not set, go to next step. If any DTC is set, go to that test first.
  2. Perform DTC CONFIRMATION TEST . If DTC P0420 or P0430 is set, go to next step. If DTCs P0420 and P0430 are not set, problem is intermittent. System is okay at this time. See TROUBLE SHOOTING - NO CODES article.
  3. Visually inspect exhaust system for any leaks or damage. Repair as necessary and go to DTC CONFIRMATION TEST . If exhaust system is okay, go to next step.
  4. For DTC P0430, go to next step. For DTC P0420, check for open or short in Red/Black wire or Gray/Yellow wire between HO2S B1 S2 and PCM 26-pin connector C51-3 terminals No. 14 and No. 21. See WIRING DIAGRAMS article. Repair as necessary and go to DTC CONFIRMATION TEST . If wires are okay, go to step  6.
  5. Check for open or short in Red/Yellow wire or Gray/Yellow wire between HO2S B2 S2 and PCM 26-pin connector C51-3 terminals No. 24 and No. 21. See WIRING DIAGRAMS article. Repair as necessary and go to DTC CONFIRMATION TEST . If wires are okay, go to next step.
  6. Replace HO2S No. 2 at appropriate bank of engine (bank 1 for DTC P0420; bank 2 for DTC P0430) and go to DTC CONFIRMATION TEST . If problem persists, replace catalytic converter at appropriate bank of engine (bank 1 for DTC P0420; bank 2 for DTC P0430) and go to DTC CONFIRMATION TEST . If problem persists, replace PCM and go to DTC CONFIRMATION TEST .
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