Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Premature Catalytic Converter Failures - DTC P0420, DTC P0430 (PIP5232C)
Reference number: PIP5232C
Supersedes refnos: PIP5232B
PREMATURE CATALYTIC CONVERTER FAILURES - DTC P0420, DTC P0430
TECHNICAL SERVICE BULLETIN
| Affected Model(s): | 2016 and Prior GM Cars and Gasoline-Powered MST Light Duty and HD Trucks |
| Supercedes: | This PI was superseded to update Recommendation/Instructions. Please discard PIP5232B. |
SERVICE INFORMATION
The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.
CONDITION/CONCERN
Technicians may encounter a concern where the catalytic converter has come apart or has set a P0420 and/or P0430.
RECOMMENDATION/INSTRUCTIONS
If you believe the catalytic converter has failed with no apparent reason, it is recommended to inspect for a poor crimp for the coil grounds terminal on the engine block for the bank with the concern.
Technicians should inspect the ground for possible corrosion or damage at ground terminal ring, fasteners and grounding surfaces.
If no corrosion or damage is found, tighten the ground bolt to the proper torque
WARRANTY INFORMATION
For wiring repairs covered under warranty, please refer to latest version of bulletin 10-00-89-005 for warranty information on wire/connector repairs.
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.
NO RELATED
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
Affiliate disclosure: We may earn a commission at no extra cost to you.
When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.