Smog and Emissions Testing in New Hampshire
New Hampshire emissions testing is required on all vehicles with a model year of 1996 or newer. Safety and emissions tests must be performed within 10 days of obtaining a registration, and repeated annually as part of the car registration process. Emissions testing centers are located throughout New Hampshire and at authorized automobile dealers. Read the sections below to learn about the importance of NH emissions testing, when and how to obtain a smog check exemption or waiver, and what to do if your vehicle fails these important tests.
New Hampshire Emissions and Smog Check Requirements
Vehicle emissions testing in NH is required along with a safety inspection to obtain and renew car registration. Drivers must have both types of inspections to receive a valid inspection sticker, which must be displayed on the vehicle as proof of meeting state requirements for safe operation on New Hampshire roadways. The mechanic performing the vehicle inspection must also provide each motorist with a copy of their official Vehicle Inspection Report (VIR). Inspection results are entered into a computer system that automatically reports the results to the NH DMV. When a car changes ownership, the new owner must repeat the safety and emissions testing process even if the original inspection sticker has not expired.
While all vehicles must pass an annual safety inspection, auto emissions testing in NH is required only on vehicles manufactured since 1996. These newer vehicles come equipped with an On-Board Diagnostics (OBD) system that monitors the performance of the engine's major systems, including emissions. DMV emissions testing must be performed on light-duty gasoline and diesel-powered vehicles with a gross vehicle weight rating (GVWR) of 8,500 pounds or less.
An OBD system emissions inspection consists of several individual tests, including the following:
- Malfunction indicator light (MIL) check during key on, engine off operation.
- Diagnostic link connector check.
- Communication with vehicle test.
- Vehicle readiness, or drive cycle check.
- MIL commanded "on" test.
- MIL light on while engine running visual check.
If the vehicle fails the OBD emissions inspection, the owner has 60 days to obtain the necessary repairs and repeat the test. One warning sign that your vehicle may not meet emission test requirements is if the check engine light, or the malfunction indicator light, comes on and remains on. This indicates that the OBD has detected a problem with the smog check and will result in an inspection rejection.
Smog Check Exemptions in New Hampshire
The only vehicles exempt from DMV emissions testing in NH are those manufactured prior to 1996. Because OBD testing is the state's only form of emissions testing, cars without these diagnostic systems are automatically exempt. Note that every vehicle must have an annual safety inspection even if it is exempt from emissions testing, and antique vehicles 40 years or older receive safety inspections biennially during the month of April.
Out-of-State Emissions Testing in New Hampshire
If your New Hampshire vehicle inspection expires while you are out-of-state, you can obtain a 30-day inspection permit by submitting a request in writing. Send your request to:
NH Dept. of Safety
DMV - Registration
23 Hazen Drive
Concord, NH 03305
Emissions Waivers in New Hampshire
New Hampshire offers an emissions testing Economic Hardship Waiver to qualifying car owners whose vehicles pass the safety inspection but fail the emissions inspection. It is intended to allow drivers more than 60 days to save up money for any necessary OBD repairs. To obtain a car emission test waiver application, contact the NH DMV OBD Program at (603) 227-4026.
Testing Fees in New Hampshire
The smog check price in New Hampshire is not capped or mandated in any way by the state. Each emissions testing station sets their own price, usually between $20 to $50 per vehicle. Call ahead to check the emission test cost at your nearest testing facility. Many offer smog check coupons or other incentives to make vehicle emissions testing more affordable.
Where to Perform an Emissions Check in New Hampshire
NH emissions testing locations can be found throughout the state. Drivers wondering, "Where can I find emissions testing near me?" need only to visit their nearest authorized automobile dealer or state-licensed inspection station. These smog check stations are required by the state to post a notice stating that the station is authorized to conduct inspections. Although many mechanics are certified to provide safety and emissions tests, your usual mechanic might not be. To be eligible for an emissions testing waiver, you must have any OBD-related repairs done by a state-certified mechanic.
Failing a New Hampshire Smog and Emissions Test
There are many reasons a vehicle might fail a New Hampshire smog check. Rejection reasons include:
- The system was not ready for testing due to recent repairs or a recently disconnected battery.
- The vehicle's failure to communicate with the smog test system, often due to a faulty data link connector.
- The check engine light is on.
If your vehicle fails the auto emissions testing, you must have the proper repairs performed before testing again. New Hampshire grants a one-time, 60-day repair period to allow time for necessary emissions certification diagnostics, repairs and retesting.