What causes duramax LB7 engine to smoke at idle?

The Duramax LB7 engine may smoke at idle due to several factors, including injector issues, such as leaking or failing injectors that can introduce excess fuel into the combustion chamber. A clogged air filter or malfunctioning turbocharger can restrict airflow, leading to incomplete combustion and smoke. Additionally, low fuel quality or improper timing can also contribute to smoking at idle. Regular maintenance and diagnostics are essential to identify and resolve the underlying issues.