Maryland Emissions

There are a number of Emissions test in the state of Maryland that may be useful and are required in a number of cases. You should look into the different tests in order to learn which ones are required for your vehicles so that you are able to stay compliant with state regulations that have been put in place.

On Board Diagnostics Test

This test is required for:

  • Passenger Vehicles and light duty trucks that were made since 1996
  • Heavy duty vehicles up to 14,000 pounds that are newer than 2008

When this test is administered, a scan tool attached to the vehicle’s On-Board Diagnostics computer, which is usually located under the dashboard. The system is then checked to see if emissions control components are in working order and if there are any that may be failing. This may cause the vehicle to produce emissions that are more than the allowable limits.

You should first look to see if the vehicle’s check engine light has been turned on and if so, you will need to take the vehicle to the dealer or a repair technician before bringing it in for a test. If you have had any repairs recently that required the battery to be disconnected, drive the vehicle for one week before bringing it in for testing.

Idle Tailpipe and Gas Cap Test

This test is required for:

  • Passenger vehicles and light duty trucks that were made between the years 1977 and 1995
  • Heavy duty vehicles up to 14,000 pounds that were made between the years 1977 and 2007
  • Heavy duty vehicles between 14,000 and 26,000 pounds that were made after 1977.

To prepare for this test, your should operate your vehicle at highway speeds for a minimum of 20 minutes before testing in order to warm up the vehicle. A valid exhaust sample will need to be taken and the vehicle will fail if there are holes or leaks.

Your vehicle will also fail if the gas cap is leaking or missing, damages or not the right cap for your vehicle. You catalytic converter must also be in place an undamaged.

Important Information

You will receive a notice about eight weeks before you need to have your vehicle tested. When you receive this notice, you need to bring your vehicle in to be tested before the deadline and present it at any of the testing stations.

If you do forget your notice, your registration card can serve as a substitute. In order to begin the test, pull into the lane marked test, leave the vehicle running and place it in park. Nothing is disconnected, but a certified emissions inspector will be looking for leaks, excessive smoke, signs of tampering with the exhaust system, a gas cap, warning lights, and worn tires.

If you vehicle does not pass, you will need to have the repairs completed and the vehicle retested. The initial fee is $14 and you can have the first retest completed for free. You can talk to the station representative before you leave if your vehicle does not pass in order to learn the areas that need to be repaired.