Why is your Chevrolet avalanche failing emissions test?

Your Chevrolet Avalanche may be failing the emissions test due to several potential issues, such as a malfunctioning catalytic converter, faulty oxygen sensors, or a check engine light indicating a problem with the engine's performance. Other common causes include leaks in the exhaust system or issues with the fuel system, such as a dirty fuel injector or a failing mass airflow sensor. It’s essential to diagnose the specific issue using an OBD-II scanner to pinpoint the exact cause before repairs. Regular maintenance can also help prevent emissions problems.