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Home >> Suzuki >> 2006 >> Grand Vitara Base, AWD, Automatic >> Repair and Diagnosis (Single Page) >> Engine Performance >> System >> Engine General Information And Diagnosis >> Diagnostic Information And Procedures >> DTC P0420/P0430: Catalyst System Efficiency Below Threshold (Bank-1/-2) >> 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 or bank-2) circuit check 
  1. Check signal and ground circuits of HO2-S (bank-1 or bank-2) for high resistance referring to applicable step of DTC P0137/P0138: O2 SENSOR CIRCUIT LOW VOLTAGE/HIGH VOLTAGE (SENSOR-2, BANK-1)  or DTC P0157/P0158: O2 Sensor Circuit Low Voltage/High Voltage (Sensor-2, Bank-2) .

Are they in good condition? 		 Go to Step 4. Repair or replace.
4 
  1. Replace exhaust manifold (built in warm up three way catalytic converter) and exhaust center pipe (built in three way catalytic converter).
  2. Perform DTC CONFIRMATION PROCEDURE .

Is DTC P0420 (P0430) still detected? 		 Substitute a known-good ECM and recheck. System is in good condition.
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