Frequently Asked Questions

What Vehicles Are Affected?

All automobiles and light-duty trucks with a model year 20 years old and newer must pass an OBD emission system inspection during its inspection period. The OBD test will be performed using the NHOST unit.

Where Do I Get My Vehicle Tested?

You can have your vehicle tested at any state-licensed inspection station. The odds are your regular mechanic will be able to provide you the service and inspections you need.

What Is the Fee for the Emissions Inspection?

The state does not regulate fees charged by inspection stations. It is recommended that you shop around to compare prices before having your vehicle inspected.

What If My Vehicle Does Not Pass the Emissions Test?

The OBD portion of the inspection is Pass/Fail for vehicles with a model year 20 years old and newer. Vehicles more than 20 years old do not require the emissions test.

If your vehicle is 20 years old or newer and is rejected for OBD, you have 60 days to correct the problems and get a retest. Be sure that your vehicle is diagnosed and repaired by a qualified OBD trained technician. Generally, mechanics who are qualified to diagnose and repair OBD are ASE L-1 certified.

Why Do I Have to Get a Vehicle Emissions Test?

The vehicle inspection program, which was designed to meet Federal EPA Clean Air Act requirements, includes checking the OBD system in newer vehicles. The OBD system is responsible for monitoring the proper functioning of the emission control system. If the OBD system is running properly, it helps to ensure the vehicle runs as efficiently as possible and that it releases a minimum of harmful exhaust.

Where Can I Get More Information?

In addition to the information on this site, you can visit the government sites below for more information on the use and benefits of OBD testing and maintenance.

NH DMV
US EPA
US EPA - OBD Information

How Long Will the Emissions Test Take?

The emissions test adds only a few minutes, at most, onto the inspection process.

How Often Does My Vehicle Have to Be Tested?

The OBD emissions test is an addition to the normal vehicle safety inspection. As such, the emissions test is performed at the same time you get your safety inspection. This will be annually for most vehicles, but some business or fleet vehicles need to be inspected two times a year.

What If I Disagree with My Inspection Results?

Certain inspections may qualify for Referee Action. If you disagree with or would like more information about your inspection results, contact the Consumer Helpline at 1-800-295-5276.