<p>Oxygen sensors monitor the air-fuel mixture in your engine. When O2 sensors wear out or fail, they can cause incorrect fuel delivery and increased emissions. This often leads to a failed smog test and poor fuel economy. Replacing faulty sensors helps restore proper engine performance and emissions compliance.</p>

<p>The catalytic converter reduces harmful exhaust emissions before they exit the vehicle. If it becomes damaged, clogged, or inefficient, emissions levels can exceed allowable limits, resulting in a smog failure. Catalytic converter issues are a common reason vehicles fail smog inspections, especially on higher-mileage vehicles.</p>

<p>The EVAP (evaporative emissions) system prevents fuel vapors from escaping into the atmosphere. Cracked hoses, faulty purge valves, or damaged components can trigger fault codes and cause a smog failure. EVAP system leaks are one of the most common reasons for a failed smog test in Las Vegas.</p>

<p>A rich or lean fuel condition occurs when the engine receives too much or too little fuel. These conditions can increase emissions and reduce engine efficiency, leading to a failed smog inspection. Fuel mixture problems are often caused by sensor issues, vacuum leaks, or fuel system malfunctions and require proper diagnostics to correct.</p>