Understanding Massachusetts Vehicle Emissions Testing

Understanding Massachusetts Vehicle Emissions Testing

Massachusetts is part of a federally required program to reduce air pollution through annual vehicle emissions testing. If your car is model year 2008 or newer, it will be tested using the On-Board Diagnostics (OBD) system during your state inspection.

The OBD test looks for:

• ❌ Emission control system malfunctions
• ❌ Check engine lights that are active
• ❌ Readiness monitors that haven’t completed

If your car fails emissions, you’ll receive a rejection sticker instead of a pass. You’ll need to fix the issue and return for a free re-inspection within 60 days.

Some garages offer diagnostics or repairs on-site, while others refer you to a mechanic. You can search our site for stations that provide both inspections and emissions repair services.