Tennessee Smog Check / Emissions Test
Residents in the State of Tennessee residing in a county with mandatory testing must get their vehicles to pass a vehicle emissions test before being able to obtain a Tennessee vehicle registration or registration renewal. New Tennessee residents that move to qualified counties have similar requirements.
Requirements to Pass the Tennessee Smog Check
Gas and diesel vehicles weighing less than 10,500 lbs and made in 1975 or newer, must get a Tennessee smog check if the vehicle owner registered the vehicle in one of the following counties:
Also, the following vehicles are NOT exempt from passing a Tennessee smog check:
- Salvaged vehicles
- Homemade vehicles
- Hybrid vehicles
- Rebuilt vehicles
Smog Check Exemptions for Tennessee Drivers
The State of Tennessee exempts the following vehicles from state smog check requirements:
- Brand new motor vehicles getting their first registration
- Vehicles weighing more 10,500 lbs
- *Electric vehicles weighing less than 8500 lbs (this does not include hybrids)
- Vehicles that are temporarily out of state
- Vehicles with antique registrations
- Gasoline vehicles weighing less than 8500 lbs made before the 1975 model year
Vehicle owners who are out of state or out of the testing area during time period for which they must get their vehicle tested for a registration renewal can apply for an exemption. To do so, Fill out and mail a Tennessee Application for Vehicle Exemption (Form CN-1026) to the address on the form. For more information call (615) 532-8378 or toll-free 1-866-329-9632 to find out about waiver application requirements. Vehicle owners out of state when their smog check is due must get their vehicle checks once they return to Tennessee.
Smog Check Fees
Smog checks fees in the State of Tennessee are $9. Testing stations accept cash (no bills larger than $20) and credit cards (Visa, Mastercard, and Discover)
Performing Emissions Testing in Tennessee
Vehicle owners must get their vehicle to pass a vehicle emissions test within 90 days before the testing due date passes. Owners also have up to 90 days after they get the testing completed to get their vehicle registered. Tests must be done every year. When bringing a vehicle to a testing location, owners must be sure to bring the following:
- Vehicle inspection packet(s)
- Vehicle registration
- Vehicle title or bill or sale
- Testing fee (Checks and tender above $20 will not be accepted)
Test personnel will present the vehicle owners with a Tennessee Emissions Inspection Compliance Certificate once their vehicle passes its vehicle emissions test. Use the certificate to show proof the vehicle passed its emission test when obtaining a Tennessee vehicle registration. The best time to get a vehicle emissions test is during the middle two weeks of the month during the early morning or in the evening.
The State of Tennessee uses the following test methods to insure vehicles meet the state’s emissions testing requirements:
On Board Diagnostic Tests: Tennessee test personnel administer an ODBII test on most gasoline motor vehicles made in the 1996 or newer model years registered in one of the 7 counties requiring vehicles to pass an emissions test. The OBDII system installed in U.S. manufactured vehicles made in the 1996 and newer model years is a mechanical issue early-warning system. The system records the vehicle’s performance by administering a specific kind of test referred to as a “Monitor”. Certain monitors test a vehicle’s primary emissions components and subsystems. While the key is in the ignition and the engine is off, a test technician will make sure the vehicle’s DLC (Data Link Connector) works properly. Then, the test technician hooks an emissions diagnostic tool up to your vehicle’s DLC using a cable to allow the technician’s diagnostic tool to communicate with the vehicle’s OBD II system. A Tennessee test technician can check your vehicle’s engine and emissions systems, and see if any monitors state a “Not Ready” status. The test personnel can complete the test in around 2 minutes.
Visual Catalytic Converter Inspection: Tennessee test technicians administer a visual inspection of all vehicles made in the 1996 model year or newer that came with a catalytic converter installed in them. Test technicians check to make sure a vehicle has a catalytic converter, that the catalytic converter does not show signs of tampering, and that the converter is in good working order.
Visual Gas Cap Check: Tennessee test technicians will do a visual inspection of a vehicle’s gas cap to see if the gas cap has a good seal and does not have any cracks.
Pressurized Gas Cap Check: Tennessee test technicians will hook up the gas cap to a pressurized gas cap testing tool to see if the gas cap can withstand pressure and not leak.
Smoke Opacity Test: Tennessee test technicians attach an smoke opacity testing probe to the exhaust of a diesel vehicle to test for the amount of particulate matter and pollutants coming out of the exhaust.
Vehicles made in a model year older than 1996 may be required to pass a visual tampering and tailpipe test instead of a gas cap leak test. Test technicians will let vehicle owners which tests they will perform on their car beforehand.
Failed Smog Inspections – Next Steps
If a vehicle does not pass a smog inspection, then the owner must get the vehicle’s emissions-related repairs completed and get the vehicle to pass a retest. Vehicle owners can receive a free diagnostic test from any Automotive Service Excellence (ASE) Certified repair technician in the state after an initial failed smog inspection.
If a vehicle continues to not pass smog inspections after the first reinspections, the vehicle owner may be eligible to apply for either a Cost or Hardship Waiver. To learn more about these waivers, call (615) 532-8378 or toll-free 1-866-329-9632.
Moved to Tennessee – Smog Check Requirements
New Tennessee residents must get their vehicles to pass a smog check before they can obtain a Tennessee vehicle registration if they move to a county where vehicles must pass a smog check.
Transferring a Vehicle Title in Tennessee – Smog Check Needed?
When transferring a vehicle title in the State of Tennessee, if the vehicle is up for registration renewal or does not have a current smog check certification, then the new owner must get the vehicle to pass a smog check before obtaining a new registration for the vehicle.
Do Sellers Give Buyers a Valid Smog Certificate?
If buying a vehicle in the State of Tennessee, the buyer must get the vehicle to pass a smog check if the vehicle does not currently have a valid smog certificate. The vehicle will have to have a valid smog certificate before an owner can receive a Tennessee vehicle registration.
Special Tips to Pass the Tennessee Emissions Test
Tennessee vehicle owners may want to get their vehicles tested as soon as they receive their first testing notice. Allow extra time to get any needed repairs done before the vehicle’s registration expires. Also, if a vehicle owner plans to be out of town during the date when their registration expires, planning early will give owners time to meet the deadline. Here are some tips to keep in mind to ensure passing a Tennessee vehicle emissions test:
- Make sure the vehicle does not have its “Check Engine” light on; If it does, it will not pass the test. To fix, check to make sure the gas cap is on tight and is not broken. Keep the sealing surfaces in the cap clean so it can make a good seal. If it is not, tighten it and drive around to see if the light goes off.
- Follow the vehicle’s recommended maintenance schedule. Many of the mechanical issues that cause vehicles to fail their tests can be addressed during a routine check-up
- If your vehicle is a make and model year when catalytic converters came standard on the vehicle, make sure your it has one, and is not malfunctioning; If it does not have one or it is not working, the vehicle will not pass the test
- Allow your vehicle to run for at least 10 minutes before it takes a test to insure an accurate reading
- Research your vehicle manufacturer’s recalls, Technical Service Bulletins (TSBs), and warranties before getting any repairs done. The cost of the repair maybe covered by the manufacturer.
- If your vehicle’s On Board Diagnostic (OBDII) system is showing trouble codes, make sure to get them fixed by a certified emissions mechanic. Do not just try to clear the codes.Test personnel will know and the vehicle will not pass inspection.
- If your vehicle is misfiring when it is idling, make sure to get this addressed before getting an emissions test
- If a vehicle’s battery is brand new, drive the vehicle for a couple of days before taking it to get an On Board Diagnostics test so as to allow the OBD system to reset
- Make sure the vehicle’s oil is not dirty. Get the oil changed on a routine basis
- Maintain the recommended air pressure in your vehicle’s tires
- Inspect your vehicle’s hoses and belts for wear. Get them replaced if necessary
- Get any mechanical issues with your vehicle’s transmission addressed and fixed. Transmission problems can affect your vehicle’s emissions and cause your vehicle to fail an emissions test
- If your motor vehicle’s emissions system has a mechanical issue, check your manufacturer’s warranty. Federal law states emissions systems on vehicles made in the 1995 and newer model years must have their emissions systems warrantied for two years or 24,000 miles
- If the OBDII diagnostic system or catalytic converter on your vehicle made in the 1995 model year or newer has a mechanical issue, check the manufacturer’s warranty also. Federal regulation states these vehicles must have a warranty on their OBDII and catalytic converters for eight years or 80,000 miles.
Find Smog Check Stations Near Me
To stay in compliance of the State of Tennessee’s smog check requirements, Tennessee-registered drivers must get their vehicles to pass a vehicle emissions test if they live in certain regions of the state. Check out our DMV & Emissions Testing Locations in Tennessee pages below to find a DMV office or testing location in your area.
Smog Check Stations in Chattanooga, Tennessee
The City of Chattanooga, in Hamilton County, Tennessee, has a population of 178,000. Tennessee-registered drivers with vehicles that require testing and living in Hamilton County must get their vehicles to pass a smog check. Check out our DMV & Emissions Testing Locations in Chattanooga, Tennessee page to find a DMV office or testing location in your area.
Smog Check Stations in Murfreesboro, Tennessee
The City of Murfreesboro, in Rutherford County, Tennessee, has a population of 137,000. Tennessee-registered drivers with vehicles that require testing and living in Rutherford County must get their vehicles to pass a smog check. Check out our DMV & Emissions Testing Location in Murfreesboro,Tennessee page to find a DMV office or testing location in your area.
Smog Check Stations in Franklin, Tennessee
The City of Franklin, in Williamson County, Tennessee, has a population of 75,000. Tennessee-registered drivers with vehicles that require testing and living in Williamson County must get their vehicles to pass a smog check. Check out our DMV & Emissions Testing Locations in Franklin, Tennessee page to find a DMV office or testing location in your area.