If you live in California, passing a smog check is an essential step in renewing your vehicle registration. But many drivers are caught off guard when their car fails—often due to preventable issues. At AB Smog Check in Monterey Park, we want to help you avoid the stress and ensure your test is smooth and successful. Here’s how to prepare for your smog check the right way.
1. Drive Your Car Before the Test
Engines run more efficiently when they’re warm. If your car has been sitting for a while, take it for a 15–20 minute drive before heading to the smog station. A warmed-up engine helps the catalytic converter and emission system function properly, increasing your chances of passing.
2. Make Sure Your “Check Engine” Light is Off
This is the number one reason vehicles fail a smog test. If the light is on—even for a minor issue—you will automatically fail. Visit a trusted mechanic (or our repair techs) to diagnose and fix the issue before testing.
3. Check Your Tires and Battery
Low tire pressure or a weak battery may not directly cause you to fail, but they can affect the onboard diagnostic system. If your battery was recently disconnected or replaced, your vehicle may not be “ready” for the test until it has completed its internal drive cycle. That could result in an automatic fail, even if your emissions are clean.
4. Change Your Oil
Dirty oil can release pollutants that get detected during a smog check. If your oil is overdue for a change, do it before the test. Be sure to use the manufacturer-recommended grade and weight.
5. Use a Fuel Additive (If Necessary)
For high-mileage vehicles, a quality fuel additive can help reduce carbon buildup in the engine and emissions system. This isn’t always necessary, but it can be helpful for older or borderline vehicles.
6. Avoid Testing Right After Repairs
If you just had major work done—especially engine or emission-related—your vehicle may not have completed its drive cycle. Wait at least a few days and drive 100–200 miles to ensure the internal monitors reset properly.
7. Don’t Clear Trouble Codes Right Before the Test
Erasing your car’s error codes or disconnecting the battery resets the onboard computer, which will show “not ready” during your test. Wait until your vehicle has completed its drive cycle after any reset.
✅ Final Checklist Before You Visit AB Smog Check:
- Drive for at least 15–20 minutes before your appointment
- Check engine light is off
- Oil is clean and recently changed
- Tires inflated and battery charged
- No recent resets of onboard diagnostics
Why Choose AB Smog Check in Monterey Park?
At AB Smog Check, we’re STAR-certified, ASE-trained, and dedicated to making your test fast, fair, and stress-free. We test all types of vehicles—including hybrids, diesels, and CNG—and we offer a free re-test if your car doesn’t pass the first time.
No appointment needed — just drive in!
