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Home >> Suzuki >> 2005 >> Grand Vitara EX, RWD >> Repair and Diagnosis >> Engine Performance >> Engine Control Systems >> Engine General Information And Diagnosis >> H25 Engine >> Diagnostic Information and Procedures >> DTC P0420 / P0430: Catalyst System (Bank-1 / -2) Efficiency below Threshold >> DTC Troubleshooting
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DTC Troubleshooting

DTC TROUBLESHOOTING CHART

Step Action Yes No
1 Was "Engine and Emission Control System Check" performed?  Go to Step 2. Go to "ENGINE AND EMISSION CONTROL SYSTEM CHECK  ".
2 Exhaust system visual inspection 
  1. Check exhaust system for leaks, damage and loose.

Is it in good condition? 		 Go to Step 3. Repair or replace.
3 HO2S bank-1 (bank-2) -2 circuit check 
  1. Check "RED/BLK" and "GRY/YEL" wire harness ("RED/ YEL" and "GRY/YEL" wire harness).

Are they in good condition? 		 Go to Step 4. Repair or replace.
4
  1. Replace bank-1 (bank-2) HO2S-2 WU-TWC converter.
  2. Perform DTC confirmation procedure.
Is DTC P0420 (P0430) still detected? 		 Substitute a known-good ECM (PCM) and recheck. System is in good condition.
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