Smog and Emissions Testing in Tennessee

Emissions testing in Tennessee is an important part of regular vehicle inspection and overall maintenance. The purpose of the car emission test is to make sure that the cars on the road are not giving off dangerous levels of emissions that may turn into smog. Not only is smog harmful to the environment, but it is also a significant health hazard.

In some counties, a smog test is required at the time of vehicle registration renewal. After passing the emissions check, the car owner will receive smog certification that must be turned in to the DMV at the time of registration renewal.

This section on smog testing in Tennessee will cover a variety of topics, including details on:

  • Tennessee emissions and smog check requirements
  • Smog check exemptions in Tennessee
  • Out-of-state emissions testing in Tennessee
  • Emissions waivers in Tennessee
  • Testing fees in Tennessee
  • Where to perform an emissions check in Tennessee
  • Failing a Tennessee smog and emissions test

Tennessee Emissions and Smog Check Requirements

Tennessee emissions testing is generally administered using the onboard diagnostic (OBD) test. The OBD smog check is able to detect high levels of harmful emissions and determine if a vehicle is at risk for emitting dangerous levels of smog in the future. Auto emission testing by use of OBD is done by checking the Malfunction Indicator Light (MIL) and using a digital tool to scan and check the functionality of car parts that reduce the amount of toxic emissions.

There is an extra step of the vehicle inspection in TN if the car was manufactured after 1996. Newer vehicles will also undergo a catalytic converter test, as well as an inspection of the gas cap. Cars with a model year older than 1996 may need an additional inspection, called the three-point tampering check. This part of the smog check inspection is administered to ensure that the emissions reading was not manipulated to pass the test.

Smog Check Exemptions in Tennessee

There are many TN DMV emissions testing exemptions because smog tests are only required in select counties. Safety and emissions testing is required only in these counties because they tend to be metropolitan areas, which are highly vulnerable to the effects of smog. None of the counties in Tennessee require smog certification for electric cars and motorcycles. Hybrid cars must still undergo the car emission test because they partially run on gasoline.

An exemption for the car emission test may also be given to permanent legal residents of TN who are temporarily residing elsewhere. Smog check exemptions are only given in these cases if the car owner will be living outside of Tennessee for a period of time longer than 90 days and is residing more than a two-hour drive away from the nearest testing station.

Car owners in Tennessee are exempt from regular emissions inspection if they do not reside in the following counties:

  • Davidson County.
  • Hamilton County.
  • Rutherford County.
  • Sumner County.
  • Wilson County.
  • Williamson County.

Out-of-State Emissions Testing in Tennessee

The way emissions inspections are regulated for permanent residents who are temporarily living outside of Tennessee is a bit different. A safety and emissions test exemption is given to residents who are living elsewhere for a period of 90 days or longer and are more than a two hour drive away from the nearest testing location. However, out-of-state car owners will be responsible for taking the car smoke test as soon as they return to Tennessee. Failing to adhere to these policies may result in future exemption request being denied.

Emissions Waivers in Tennessee

A DMV smog check cannot be waived in TN, even in special circumstances. If vehicle emissions testing is mandatory for a car owner in the state, he or she must take the test or be subject to various penalties. Car owners who do not pass the emissions check need to get the necessary repairs to address the smog issue. However, retaking the auto emissions testing can be taken for free if the car owner makes the repairs within 90 days of taking the first test.

Testing Fees in Tennessee

Emissions testing in Tennessee is administered for a fee. The smog test price is the same for all vehicles that must undergo an inspection, regardless of the make, model, fuel type or weight. The emission test cost is $9, and car owners have 90 days from the emission registration expiration date to receive a smog check without accumulating additional fines. If a car owner fails the vehicle inspection, he or she will be able to retake the test once for free. The car owner must pay full smog check price for any additional retakes.

Where to Perform an Emissions Check in Tennessee

“Where can I find emissions testing near me?” is a common question asked by car-owning residents who live in TN. Given that auto emissions testing is only required in some Tennessee counties, all of the emissions testing stations are concentrated in certain areas. Even so, there are several emissions testing locations throughout these counties for the convenience of car owners, including in cities like Nashville, Madison and Hermitage.

Most smog check stations in TN are open from 7 a.m. to 6 p.m. on Monday and Tuesday, 7 a.m. to 5 p.m. from Wednesday through Friday and closed on weekends. However, there are two Nashville emissions testing centers that are open on Saturdays from 9 a.m. to 4 p.m.

Failing a Tennessee Smog and Emissions Test

In addition to Tennessee emissions testing being mandatory for certain car-owning residents, it is also required that all vehicles pass the evaluation. This means that even if a vehicle fails the safety and emissions test, the car owner is responsible for retaking the test until he or she earns a passing score.

If a vehicle fails the emissions inspection, the owner will receive a detailed report of the reasons why the vehicle did not pass. The Nashville Vehicle Inspection Program (VIP) will also check failed vehicles at no cost, though VIP does not offer repair services. Vehicles with the model year of 1995 and older will need to take the entire smog test over again, while newer cars will only retake the specific failed portion. If the car owner repairs these issues within 90 days of the initial vehicle inspection, the retake will be administered for free. Each additional smog certification retake will follow the same pattern: pay for one safety and emissions test, the next one will be free.

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