Emission Testing in Texas

If you’re registering a car in Texas, chances are the Department of Public Safety (DPS) to go through the process of Texas Emissions testing. The emissions test is one half of your vehicle inspection. The other half is a safety inspection to check that all the outer parts of your vehicle are working correctly. The emissions test can be confusing, especially if the mechanic finds a problem with your vehicle. We’re going to break it down piece-by-piece so you know exactly getting an emissions test means for you and your vehicle.

What Is Emission Testing?

So what is an emissions test? This test is used to test your car’s emissions to make sure your car isn’t smogging up the air quality. When you take your vehicle in to get an inspection, the emissions test will be part of the entire testing process. Besides making sure all your gizmos and gadgets are working properly, your car (depending on the model year) will have one of two types of emissions inspections ran on it. These tests determine if your car’s emissions are up to environmental carbon monoxide standards. Let’s discuss which test you’ll get when you take your car to be inspected.

The On-Board Diagnostics: Second Generation (OBDII) Test

The On-Board Diagnostics: Second Generation (or OBDII for those in the know) test, is done on motor vehicles whose model year is 1996 or newer. It is a computerized part of your car that monitors your emissions, so while you’re driving around, it’s keeping records of what’s happening.

When you take your car to get inspected, the mechanic will use a scanner to check out what’s been going on with your emissions system and its components, by downloading the computer’s stored info. If your OBDII senses a problem with your vehicle’s emissions, such as your Check Engine light turning on, it creates a diagnostic trouble code (DTC) that is stored in the computer’s memory. When the computer is scanned, the mechanic can see the info from these DTCs and can then determine whether your vehicle passes its inspection.

Acceleration Simulation Mode/Two-Speed Idle (ASM/TSI)

If your car has a model year of 1995 or older, you will have the Acceleration Simulation Mode test. This test is an upgrade from the older Two-Speed Idle test. Because of the age of these vehicles, they do not have on-board computers for mechanics to plug into and scan. This means both of these tests are tailpipe-based, meaning they test the levels of emissions coming from your vehicle when it’s running.

The ASM measures levels of NOx, CO2, HC, & CO by simulating acceleration and average driving conditions. The TSI measures CO2, HC, and CO by measuring your vehicle’s emissions at two speeds/RPMs: high speed & idle.

You are exempt from the emission inspection if you live outside of the following counties: Brazoria, Fort Bend, Galveston, Harris, Montgomery, Collin, Dallas, Denton, Ellis, Johnson, Kaufman, Parker, Rockwall, Tarrant, Travis, Williamson and El Paso.

Based on where you live, you’ll receive one of these tests.

  1. TSI: El Paso area, Travis/Williamson Counties
  2. ASM: Dallas/Fort Worth, Houston/Galveston areas

You are also exempt from the emission inspection if your motor vehicle does not use gasoline (it’s electric – boogie woogie woogie) or if it uses diesel fuel. As you probably guessed, hybrid vehicles are not exempt because they still use gasoline.

What If I Don’t Pass My Emission Test?

If you don’t pass the emission inspection, you have a few options:

The first is that you can get it fixed (or fix it yourself if you’re handy like that) it and re-test after it’s fixed. If it still doesn’t pass inspection, you may be eligible for an extension or a waiver. Check out TCEQ’s site to see if your vehicle qualifies.

If your vehicle doesn’t pass the emission test and you are worried about the amount of money it will take to fix it, you may be able to apply for the Drive a Clean Machine Program. This program allows you to apply for money toward replacing your vehicle ($3500) or repairing your vehicle ($600). Eligibility is based on net family income and your vehicle must have already passed the safety inspection. To qualify for the repair assistance, you must get your motor vehicle repaired at a state-recognized RERF (Recognized Emission Repair Facility) inspection station.