Inspection Tips for Diesel Vehicles

Which model-year vehicles require a safety inspection?

The State of Utah requires a safety inspection for most diesel-powered vehicles according to the same schedule as gasoline-powered vehicles at a frequency depending on the age of the vehicle.

  • For newer diesel vehicles, a safety inspection is required when the model year is four, eight and ten years old.
  • For diesel vehicles ten years and older, it must pass a safety inspection every year.

Which vehicles require an emission inspection?

Most counties do not require an emission inspection on diesel vehicles, however Salt Lake County (see requires diesel vehicles model year 1998 and newer with a weight up to 14,000 pounds to undergo an emissions test according to the same schedule as gasoline-powered vehicles.

Tips for newer model-year vehicles:

Vehicles model-year 1996 and newer undergo a scan of the On-Board Diagnostic (OBD) system to help determine if the vehicle's emission control systems are operating properly. The State of Utah's passing criteria combines data from the OBD with a visual inspection.

The following tips will help your diesel vehicle pass its inspection, and at the same time help the environment!

  • Regular maintenance
    Change your oil and filters as recommended by your vehicle's manufacturer (usually every 3 months or 3,000 miles) to help your vehicle operate efficiently and increase its odds of passing the emission test. It is also important to use the type of oil and fuel recommended by the manufacturer for best performance.
  • Watch for leaks
    Low fluid levels can affect the efficiency and performance of your vehicle, which can cause a test failure.
  • Gas cap required
    State regulations require that your gas cap is in place and is of the correct type for your vehicle to avoid excess evaporative emissions.
  • Watch for warning lights
    The same "On Board Diagnostics" system in your vehicle that triggers the warning light is the same system that reports its information to our inspection station's computer determining if your vehicle meets state requirements, so if your vehicle's computer is triggering a "Check Engine" light, it may not pass the inspection.
  • New or disconnected battery?
    If your battery is disconnected, or if it died and needed a jump start, your vehicle's computer system resets itself and would fail due to a lack of data even if your vehicle is operating properly. Driving between 100 - 150 miles (consult your vehicle's manual for an exact number) before coming in for your inspection will make sure your vehicle has gathered enough information for its test.

Extra tips for older model-year vehicles:

State and county requirements for model years older than 1996 are a little different as these older vehicles don't have the computer systems installed to report information about the vehicle's performance.

  • Plan a little extra time
    Older vehicles require a longer inspection process and may take a little longer, usually around 20 minutes from start of the inspection to getting back on the road.
  • Watch for warning signs
    Road-weary vehicles can start to show signs of a faulty emissions system, including difficulty starting or staying running at idle, jumping or shaking at higher speeds, and misfires. Taking your vehicle to a certified repair shop as soon as you notice a worsening trend can catch problems before they escalate into a more major repair or test failure.

Visit a DEKRA station for more expert advice and a fast, professional vehicle inspection. Download a $5 off coupon for your vehicle's next inspection!


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The State of Utah answers questions on registration and inspection program rules.

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