Your Guide to Utah's Emissions Test: What Salt Lake County Drivers Need to Know
Your Guide to Utah's Emissions Test: What Salt Lake County Drivers Need to Know
If you live in Salt Lake City, Taylorsville, or anywhere in Salt Lake County, you’ve likely heard about the emissions test. It’s a mandatory part of registering your vehicle, but for many drivers, the process can seem confusing. Why is it required, and what exactly are they checking?
This guide breaks down the essentials of Utah’s emissions test. We will cover why it matters for our local air quality, what happens during the inspection, and what you can do if your car doesn’t pass.
Why Does Salt Lake County Require an Emissions Test?
If you’ve ever seen the haze settle in the valley during the winter, you’ve seen the problem firsthand. Salt Lake City’s unique geography, surrounded by mountains, can trap air pollution close to the ground. This creates inversions, where a layer of warm air acts like a lid, sealing in cold air and vehicle emissions.
Cars and trucks produce pollutants like nitrogen oxides and hydrocarbons. These chemicals contribute to the smog that can make our air quality unhealthy, especially for children, the elderly, and those with respiratory conditions. The emissions test is a key tool in Utah’s effort to improve our air. It identifies vehicles that are releasing excessive pollution, ensuring they are repaired to meet clean air standards. This helps protect the health of our community and our beautiful Utah environment.
Which Vehicles Need to Be Tested?
Not every vehicle in Utah is required to have an emissions test. The rules are specific to location and vehicle type. In Salt Lake County, the general requirements are:
● Gasoline-powered vehicles — model year 1968 or newer, that are six years old or older.
● Diesel-powered vehicles — model year 2008 or newer, with a Gross Vehicle Weight Rating (GVWR) of 14,000 pounds or less.
Newer vehicles are typically exempt for the first five years. If you are unsure whether your car needs a test, you can check the registration renewal notice from the state or visit the Utah DMV website.
What Happens During the Test?
The emissions test is a quick process, usually taking less than 30 minutes. There are two primary types of tests performed at official testing stations:
- On-Board Diagnostics (OBDII) Test:
This is the most common test for gasoline vehicles model year 1996 and newer. A technician plugs a scanner into your car’s computer port, usually located under the dashboard. The computer reports the status of your engine and emissions control systems. For your car to pass, the computer must show that all its self-checks are complete and that no problems are found. - Two-Speed Idle (TSI) Test:
This test is used for older vehicles (model years 1968 to 1995). A sensor is placed in your car’s tailpipe to measure the level of pollutants in the exhaust while the engine is running at two different idle speeds.
What to Do If Your Check Engine Light is On
This is the most important rule: If your check engine light is on, your vehicle will automatically fail the OBDII emissions test.
The check engine light is a direct signal from your car’s computer that something is wrong, often with a component that affects emissions. Do not ignore it hoping the light will turn off by itself. The best course of action is to have the issue diagnosed and repaired by a professional mechanic before you go in for your test.
Common Reasons a Car Fails an Emissions Test
Several issues can cause a vehicle to fail. Some of the most frequent problems we see at our Salt Lake City shop include:
● A faulty oxygen sensor
● A loose or missing gas cap
● Problems with the catalytic converter
● Issues with the ignition system, like spark plugs or coils
● A malfunction in the evaporative emissions control (EVAP) system
Getting Your Car Ready for the Test
A little preparation can increase your chances of passing on the first try.
● Drive Your Car First: Don’t take your car in for a test when the engine is cold. A 20-minute drive on the freeway helps ensure the engine and catalytic converter are at optimal operating temperature.
● Check Your Gas Cap: Make sure it is tightened securely until it clicks. A loose cap is a common and easily fixable reason for a failure.
● Address the Check Engine Light: If the light is on, get a professional diagnosis. We can read the trouble codes and tell you exactly what needs to be repaired.
What If My Car Doesn’t Pass?
Failing the test is not the end of the road. You will receive a report detailing why your vehicle failed. You then have a set amount of time to get the necessary repairs done. Once the repairs are complete, you can return to the testing station for a free re-test.
Need Help Passing Your Emissions Test in Salt Lake County?
If your check engine light is on, or if you’ve already failed your test and need repairs, the team at Jones Complete Car Care is here to help. Our ASE-certified technicians use advanced diagnostics to quickly identify the root cause of your emissions problem. We provide clear, honest estimates and perform the necessary repairs to get your car running cleanly and efficiently.
We have three convenient locations to serve you in Salt Lake City, Taylorsville, and Clearfield. Don’t let a failed emissions test delay your vehicle registration.
Schedule a diagnostic appointment with us today, and let us help you get back on the road quickly and safely.
