How long does a smog check take in California?
Short answer: most smog checks in California take 20 to 30 minutes from the time your car pulls into the bay to the time the certificate prints. At Super Station Concord, we try to keep it closer to 20 whenever the queue allows.
The longer answer depends on a few factors — the type of test your vehicle is directed to, the age of the car, and whether the shop is running walk-ins that day. Here is how the visit usually breaks down.
Step 1: Check-in (2-3 minutes)
The technician pulls up your vehicle record in the state's VID (Vehicle Inspection Database) and confirms the test type the DMV has directed: standard, STAR-directed, or a change-of-ownership. STAR-directed tests must be done at a STAR Certified station like ours.
Step 2: Visual and OBD-II inspection (5-10 minutes)
For 2000-and-newer gas vehicles, the bulk of the test is done by plugging into the OBD-II port under the dash. The technician also performs a visual check of emissions components (gas cap, hoses, catalytic converter) and confirms readiness monitors are set.
Step 3: Tailpipe test (only on older vehicles)
Pre-2000 gasoline vehicles and diesel vehicles (1998 and newer) still get a dynamometer or probe test. This is the step people picture when they think "smog check" — and it adds about 5 to 10 minutes. Newer cars skip this entirely.
Step 4: Certificate and paperwork (2-3 minutes)
The result transmits electronically to the DMV within moments, so in most cases you do not need to bring the paper certificate to a DMV office. You get a printed copy for your records before you drive off.
What can slow it down?
- Not Ready monitors. If the car's computer was recently reset (after a battery disconnect or check-engine-light clear), the OBD-II readiness monitors may not be set. The test will fail "Not Ready" until you drive 50-150 miles to reset them.
- Check engine light on. An illuminated MIL is an automatic fail. Fix the code first, then come back.
- Paperwork hiccups. If the DMV notice has an old address or VIN mismatch, we may need a quick call to resolve it.
Can I wait at the shop?
Yes — most customers wait in our lobby with the paper or a phone. Because the test is usually 20-30 minutes, it is not worth going anywhere. We also take calls ahead so you can time your drop-in and avoid the queue.