Vehicle emissions test
Learn about emissions standards in Ontario and how we are reducing smog-causing pollutants by requiring regular emissions tests for big polluters such as commercial trucks and buses.
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Since April 1, 2019, Ontario drivers are no longer required to get Drive Clean emissions tests for their light passenger vehicles, however emissions standards still apply to all vehicles. On-road enforcement officers ensure compliance with these standards. Heavy diesel commercial motor vehicles continue to require an emissions test.
Our new enhanced emissions testing program focuses on the biggest polluters on our roads, such as commercial trucks and buses, to protect Ontario’s air quality.
Testing for heavy diesel commercial motor vehicles
Ontario is working to integrate the new vehicle emissions testing program for heavy diesel commercial motor vehicles with the annual safety Motor Vehicle Inspection Station program. This new integrated program will:
- reduce costs
- create a convenient, one-stop shop for owners/operators
- ensure the safety of our roads and the protection of our environment
There will be one test performed at the same time and location for both an emissions and safety inspection. The test will produce one digital result.
Vehicles that need to be tested
Your vehicle needs an emissions test if it is a heavy diesel commercial motor vehicle with a registered gross weight over 4,500 kilograms, such as a large truck or bus and the vehicle is:
- at least seven model years old and you are renewing your license plate sticker
- older than the current model year and you are registering the vehicle to a new owner
You will receive a registration renewal notice in the mail that will indicate if your vehicle needs an emissions test.
Your vehicle does not need an emissions test if it is a:
- light passenger vehicle (vehicles with a registered gross weight less than or equal to 4,500 kilograms), including motorcycles
- heavy non-diesel vehicle (vehicles with a registered gross weight over 4,500 kilograms that do not run on diesel)
Light passenger vehicles and heavy, non-diesel vehicles are still subject to Ontario’s emissions standards, as set out in the Environmental Protection Act and Ontario Regulation 457/19 (Vehicle Emissions). If you are found to be in contravention of the Act or Regulation, you may be subject to compliance or enforcement action such as verbal warnings, orders and/or fines.
Provincial officers anywhere in Ontario are authorized to stop and inspect your vehicle if they believe, among other things, that:
- your vehicle is emitting excessive exhaust
- emission control equipment has been tampered with or removed
Maintain your vehicle
Avoid costly repairs and reduce pollution by maintaining your vehicle according to the manufacturer’s recommended service schedules. It is illegal to drive with your Malfunction Indicator Light (the “check engine light”) on if it is emissions control-related. Have your vehicle looked at by a qualified repair technician as soon as possible if this light comes on.
If you are buying a used vehicle, you should ensure that it complies with emissions standards and does not have faulty emission controls, otherwise you may be subject to roadside enforcement action.
If you are at the end of your lease and want to buy the vehicle, the leasing company does not need to pass an emissions test to transfer ownership to you and there are no further requirements for you to get an emissions test.
Motor replacements and assembled vehicles
If you are replacing a motor in a vehicle or building an assembled vehicle, please note the following rules (the terms “hot rod” and “kit car” are no longer used in vehicle emissions regulation):
- the emission standards for a motor replacement must be at least as stringent as those met by the original motor and must have all the emissions control equipment attached and functioning
- the motor of an assembled vehicle must have all the emissions control equipment of a usual motor attached and functioning
If you have questions, please contact the Emissions Test Contact Centre at
When a vehicle needs a test
For the purposes of licence plate sticker renewal, vehicles that are subject to the emissions test are required to be tested annually. You will receive a registration renewal notice in the mail that will indicate if your heavy diesel commercial motor vehicle needs an emissions test.
If you are due for an emissions test while outside Ontario
If your vehicle is due for an emissions test and you’re currently away from the province, you can request a one-time, 6-month extension on renewing your licence plate sticker.
After 6 months, you will need to get the test in order to renew your plate sticker.
If you drive without a valid sticker, you could be subject to penalties, including a ticket and fines.
If you plan to be out of the province for 6-12 months when your registration renewal is due, please contact the Emissions Test Contact Centre toll-free at
If your licence plate sticker expires before your emissions test
You can get a temporary license plate sticker from the Ministry of Transportation if your current registration expires before you can get an emissions test.
A temporary licence plate sticker allows you to drive for up to 10 days.
This will give you enough time to:
- have your vehicle’s emissions tested
- get any required repairs done — before renewing your vehicle registration
If you drive without a valid licence plate sticker, you could be subject to penalties, including tickets and fines.
Where to get a test
Emissions tests for heavy diesel commercial motor vehicles must be performed by a certified inspector at a facility that has entered into an agreement with the Ontario government. These private operators:
- set their own fees
- run the test
- provide you with a test report
What happens during a test
An emissions test for a heavy diesel commercial motor vehicle involves:
- a pre-test check
- an opacity test
- an on-board diagnostic system test (only for vehicles between 4,500 and 6,350 kilograms)
There are measures in place to ensure emissions tests are fair, such as:
- Test facilities must have computerized, tamper-proof equipment approved for the program.
- Your test results are compared with emissions standards set for all vehicles of the same particular year and model. All results are recorded in a central database, to facilitate monitoring and auditing of test results.
- All inspectors performing the tests are monitored continuously for expected pass/fail rates and irregularities.
- All facilities are audited to ensure they follow proper testing procedures.
Before performing the emissions test, the inspector will do a visual check of the vehicle.
The inspector may find issues with the vehicle that must be corrected before you can continue with the emissions test. Issues can include:
- the vehicle has visible emissions for more than five seconds in any one-minute period
- the vehicle has a missing fuel cap or fuel cap that fits improperly
- the vehicle has exhaust leaks
- the motor governor fails, malfunctions or is maladjusted
- the vehicle identification number is missing or does not match the vehicle permit
- there is an inability to connect to the data link connector, such as because there is a device attached to the data link connector
- the testing may cause a risk to health or safety
- the testing may cause damage to equipment, property or the vehicle
An opacity test measures the opacity of the emissions from a vehicle’s exhaust. To pass the opacity test, a vehicle’s test result must not exceed the corresponding opacity percentage for its model year.
|Model year of heavy diesel vehicle||Opacity percentage|
|1990 and older||If the vehicle is not a school bus, 40%
If the vehicle is a school bus, 30%
|1991 to 2007||30%|
|2008 and newer||20%|
Opacity test exemption removal
Beginning January 1, 2021, no vehicle will be allowed to skip a year of emissions testing based on its opacity test result.
This means that if your vehicle had an opacity test result below 20% in 2019, you will still be able to skip the emissions test in 2020. However, if your opacity test result is below 20% in 2020, you will not be able to skip the emissions test in 2021.
On-board diagnostic system test
An on-board diagnostic system test helps identify whether emission control systems are operating as intended.
The on-board diagnostic test is mandatory but is currently for informational purposes only. Beginning July 1, 2021, a vehicle that fails the on-board diagnostic test will not pass the emissions test.
Emissions test results
After completing the emissions test for a heavy diesel commercial motor vehicle you may receive a:
If your vehicle passes the emissions test:
- you will get a Vehicle Emissions Report with 'pass' clearly printed on it
- use the pass report to renew your licence plate sticker
- keep the pass report with your vehicle’s maintenance information
The pass report is valid for 12 months.
Vehicles usually fail the emissions test because the vehicle has an emissions system problem.
The inspector can explain the emissions results on the Vehicle Emissions Report.
You’ll need to have your vehicle’s emissions problem repaired before you can:
- take a retest
- renew your licence plate sticker
Do not leave the test facility without the test report.
Search a vehicle’s emissions test history
- previous emissions test results
- repair history
- any Vehicle Emissions Reports that have been issued
In order to search your vehicle’s test history, you will need your Vehicle Identification Number (VIN). You can find your VIN on the:
- green ownership certificate – issued by the Ministry of Transportation
- vehicle insurance certificate (pink form) – issued by your insurance company
- Statement of Compliance label, located inside the vehicle, on the driver’s-side door opening (if the door is original)
- vehicle’s dashboard
Report a smoking or tampered vehicle
Tampering refers to removing or rendering inoperative all or part of a system or device used to prevent or lessen the discharge of any contaminant.
Please have the following information available, if possible/applicable:
- the licence plate of the vehicle
- a description of the vehicle
- the location, date and time you saw the vehicle
- the colour of the smoke
- business name and location
Report a complaint about a test facility or inspector
We have zero-tolerance for fraud or consumer abuse within the emissions testing program.
If you have any concerns, please contact the Emissions Test Contact Centre toll-free at
We are serious about protecting vehicle owners and will investigate your complaints.
Heavy diesel commercial motor vehicle on-board diagnostic non-communication exemption list
This list is made for the purposes of subparagraph 3i of subsection 13 (3) of Ontario Regulation 457/19: Vehicle Emissions.
A small number of heavy diesel commercial motor vehicles are expected to be identified with unique testing characteristics that prevent them from communicating with an on-board diagnostic test (OBD) unit. These vehicles cannot be OBD-tested to determine if the OBD system has an active emission-related Diagnostic Trouble Code (DTC).
If a vehicle is identified on the list below, a vehicle emissions report that indicates a pass may be issued under s.13 of Ontario Regulation 457/19 without the vehicle being tested for whether the OBD system has an active emissions-related DTC. Such a vehicle would need to show compliance with the opacity standards in order to be issued a vehicle emissions report indicating a pass.
This list will be updated regularly as heavy diesel commercial motor vehicles that cannot be OBD-tested are identified.
Start model year
End model year
|1||To be determined (TBD)||TBD||TBD||TBD||TBD|
On-board diagnostic monitor readiness exemption list
This list is made for the purposes of subsection 13 (2) of Ontario Regulation 457/19: Vehicle Emissions.
A small number of heavy diesel commercial motor vehicles are expected to be identified with unique testing characteristics that require exceptions to diagnostic monitor checks that are part of the on-board diagnostic test.
The on-board diagnostic test will exclude the check of monitor status for Monitor IDs that are listed in the table below for the specific vehicles identified in the table below. All other aspects of the on-board diagnostic test will apply.
This table will be updated as heavy diesel commercial motor vehicles that have unique testing characteristics for the on-board diagnostic test are identified.
Start model year
End model year
Monitor IDs excluded
|1||To be determined (TBD)||TBD||TBD||TBD||TBD||TBD|
|OBD monitor ID number||Diesel monitor name|
|5||NOx SCR aftertreatment|
|6||Exhaust gas sensor|
|10||Boost pressure system|
|11||Readiness result of A/C refrigerant|
|12||Readiness result of thermostat|
|13||Readiness result of PCV|
This table relates to column six of the OBD monitor readiness exemption table.