What Is Dyno Smog Testing and Why Older Cars Need It
October 31, 2025
If you drive a vehicle made before the year 2000, you’ve probably heard about something called a dyno smog test or BAR-97 test.
At Jim Brangham Auto Repair, we perform this type of smog testing to make sure older vehicles meet California’s emissions standards. Plus, it keeps your vehicle running clean and reliable.
What Is a Dyno Smog Test?
A dyno smog test checks how much pollution your car gives off while it’s actually running under real driving conditions. Your vehicle’s drive wheels are placed on a machine called a dynamometer, which lets your car “drive” in place. While your car runs through different speeds and loads, the system measures the exhaust gases coming out of the tailpipe.
This process is part of the BAR-97 smog testing system. This is required by the California Bureau of Automotive Repair (BAR) for most vehicles built before the 2000 model year.
Why Newer Cars Don’t Need It
Cars built after 2000
have advanced onboard computers (OBD-II systems) that monitor emissions automatically. For those vehicles, smog checks are done by plugging into the car’s computer. But older vehicles don’t have that same technology—so dyno testing helps simulate real driving to get accurate readings.
What We Look For During Testing
During a BAR-97 dyno smog test, our certified technicians measure:
- Carbon monoxide (CO)
- Hydrocarbons (HC)
- Nitrogen oxides (NOx)
If any of these levels are too high, your car may fail the test. But don’t worry—our team can help identify the cause, perform the needed repairs, and retest your vehicle to make sure it passes.
Keep Your Classic or Older Car Legal and Reliable
Passing your smog test isn’t just about staying legal—it’s also about keeping your car in top shape. A properly running engine burns fuel efficiently, saves gas, and helps protect our air quality here in Cathedral City and across California’s Coachella Valley.
Schedule Your BAR-97 Smog Test Today
If your car is older than a 2000 model year, it likely requires a BAR-97 dyno smog test. At Jim Brangham Auto Repair, we’re a STAR Certified Smog Check Station, and our team has the training and equipment to get your vehicle tested quickly and accurately.
✅ Call us today at (760) 321-7040
or click the Book Service button to schedule your dyno smog test and keep your car running clean and compliant.
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