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Catalytic Converter Trouble Codes P0420 and P0430 - keywords 4.8 5.3 6.0 6.2 back backpressure cat efficiency exhaust hesitate LC9 LMG low LY2 LY5 LY6 L76 L92 power pressure stall surge

Subject:Catalytic Converter Trouble Codes P0420 and P0430

Models:2007 Cadillac Escalade
2007 Chevrolet Suburban, Tahoe
2007 GMC Yukon



The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.

Condition/Concern:

A dealer may encounter a vehicle with trouble codes P0335, P0420, and/or P0430. It is possible to induce catalytic converter efficiency codes when a driveability symptom is caused by a faulty crank sensor or connection.

Recommendation/Instructions:

When DTCs P0335, P0420, and P0430 are found, complete the current SI diagnostics for catalytic converter trouble codes, and repair the vehicle as needed. After catalytic converter repairs are completed, inspect the crank sensor connector for loose or damaged terminals. Make sure the crank sensor connector is plugged in, properly seated, and properly locked. Use the Circuit/System Verification section of the P0335 diagnostic to monitor crank sensor operation. Replace the crank sensor if necessary.

Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.