P0422 2018 Chevrolet Silverado Code - Catalyst 2 Low Efficiency

P0422 indicates that the second catalytic converter is not operating efficiently, as detected by the vehicle's oxygen sensors.

Common symptoms include the check engine light turning on, reduced fuel efficiency, possible loss of engine performance, and an unusual exhaust smell.

The most common causes are a failing catalytic converter, damaged oxygen sensors, exhaust leaks, or engine issues causing incorrect air-fuel mixture.

Yes, but it’s not recommended for long periods. Continued driving could lead to further engine or emissions system damage.

Repairs may involve replacing the catalytic converter, replacing faulty oxygen sensors, fixing exhaust leaks, or addressing engine performance issues.

Use an OBDII scanner to confirm the code, inspect the catalytic converter and oxygen sensors for damage, and check for exhaust leaks or engine misfires.

Repair costs can vary widely. Replacing a catalytic converter may cost $1,000–$2,500, while oxygen sensor replacement typically costs $100–$300.

Yes, a failing or clogged catalytic converter is one of the most common causes of this code.

Clearing the code will turn off the check engine light temporarily, but it won’t resolve the underlying problem causing the code.

Regular maintenance, addressing engine misfires promptly, and using quality fuel can help prevent catalytic converter and oxygen sensor issues.