​​FAQ's

Nearly all diesel and alternative fuel heavy-duty trucks, buses, and other vehicles with a gross vehicle weight (GVW) rating over 14,000 pounds that operate in California are subject to the compliance deadlines mentioned above.  Affected vehicles include:

All diesel, alternative fuel, and hybrid vehicles 
All California, out-of-state (OOS), and out-of-country registered vehicles that operate within California

As of 1/1/2025, vehicles subject to semi-annual testing will be required to demonstrate compliance every six months.

Starting in 2027, this requirement will increase to testing required quarterly, 4x's a year.   

Compliance tests deadlines are aligned to the vehicles registration expiration date.     

They are due by the registration expiration date of the vehicle, and 6 months prior.   

Tests may be completed UP TO 90 days in advance of the deadline, to be compliant.   

For Example, If you registration expires in August, your compliance deadlines are the last day August, and the last day in February.    

As long as nothing has been modified to alter the emmissions on the vehicle, then it should pass.   Please ensure that any FMI codes that have appeared, are cleared at least 48 hours before your test.  

We also can do a pre-check test.   For an additional fee, we can run the test through a separate program that will produce a report, that will show if the vehicle will pass or fail.    You will receive a copy of that report.   

The test itself can take anywhere from 5 - 15 minutes.   Sometimes the OBD gets finicky with the testing cable, and struggles to connect, so it can take longer.    Initial tests take longer too, as we catalog your fleet in our system, so that we can make sure that your trucks stay compliant, and get tested in time.   

Unfortunately, yes.    At this time, we can only test trucks that are engine model year 2013 and newer.      Trucks older than this, must undergo a smoke opacity test and visual engine compartment inspection, that we do not have the equipment to perform.