Frequently Asked Questions

What Vehicles are Affected?

All automobiles and light-duty trucks whose model year is 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. Chances are, your regular mechanic will be able to provide you the service and inspections you need.


What is the Fee for the Emissions Test?

The state does not regulate fees charged by inspection stations. Inspection stations are charged $3.38 for each OBD inspection. 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 now Pass/Fail for vehicles whose model year is 20 years old and newer. Vehicles more than 20 years old do not require the emissions test.

If your vehicle is 20 years old and 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, people 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 that began in May 2005 under the recommendation of the Federal EPA Clean Air Act 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 that have 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 emission tests adds only a few minutes, at most, onto the inspection process.


How Often does my Vehicle have to be Tested?

The OBD emission test is an addition to the normal vehicle safety inspection. As such, the emission 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.


Are there any changes to the Safety Inspection?

The vehicle Safety Inspection portion of the annual vehicle inspection is unchanged. Your vehicle will still need to pass on all the points of inspection to ensure that it is safe to drive on New Hampshire's roadways.


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 NHOST Helpline at 1-800-295-5276.