Automotive Q&A

Learn about your State Emissions Inspection

What is a State Emissions Inspection?

This mandatory emissions inspection was created to meet specific regional air-quality issues and improvement goals. These inspections are part of plan to protect the environment and improve air quality by inspecting every vehicle’s emissions system. The state emissions inspection can be performed by any official Department of Transportation (DOT) service station. Any such station will have a sign to let you know they are an official DOT service station. During the emissions inspection, your vehicle goes through four different inspections. First, your vehicle’s emissions are checked. This includes idle testing, Acceleration Simulation Mode (ASM) testing, and evaporative system function tests. Second, the On-Board Diagnostics (OBD) system is checked. The OBD system is a device that detects problems in your engine. The system was put in place to help control vehicle emissions. Third, your gas cap will be inspected. This just means that your gas cap is checked to make sure that no harmful gases are escaping from your gas tank into the atmosphere. Finally, your vehicle undergoes a visual inspection. During the visual inspection, the following items are checked: catalytic converter, exhaust gas re-circulation (EGR) valve, positive crankcase ventilation (PCV) valve, fuel inlet restrictor, air pump, muffler, tail pipe, and evaporative control system components. If any of these items or inspections fail, the necessary part will need to be repaired or replaced, or your vehicle won’t pass the emissions test.