Failed Smog Check in California? Here's What to Do
If your vehicle failed California smog inspection, you have 60 days to repair and re-test before DMV registration is blocked. Free retest at STAR-certified shops within 30 days. We can diagnose + repair at our test+repair locations.
Key facts
- ✓ 60-day window to repair + retest before DMV registration penalty
- ✓ Free retest within 30 days at STAR-certified stations (where you originally tested)
- ✓ Repair cost averages ~$773 per BAR official data (March 2026)
- ✓ CAP (Consumer Assistance Program) may provide $1,200 repair assistance for income-qualified owners — apply at bar.ca.gov
- ✓ Don't drive uncertified past registration expiry — fix-it ticket + penalty
What to do
- Get the printed failure report — shows specific codes/reasons
- Bring it to our test+repair shop for diagnosis (most common: O2 sensors, EVAP, cat converter)
- Get an estimate before authorizing repair
- Apply to CAP if income-qualified — saves up to $1,200
- After repair: come back for free retest at the original STAR station within 30 days
Most common causes
- Catalytic converter failure (~40% of failures)
- O2 sensor failure (~25% of failures)
- EVAP system leaks (gas cap, purge valve)
- Engine misfire / spark plug issues
- MAF sensor contamination
- Tampered emissions equipment (deleted DPF, missing cat)
Common questions
Can I drive with a failed smog?
Yes, you can drive — but you cannot RENEW REGISTRATION at the DMV until you pass. Driving past your registration expiry date results in a fix-it ticket + penalty.
How long do I have to retest?
California gives you 60 days from your registration expiration to repair + retest. STAR-certified shops offer a FREE retest within 30 days of your failed inspection.
What's the average cost to fix?
Per March 2026 BAR data: average repair-after-fail cost is $773.49. Could be as low as $50 (gas cap) or as high as $2,500 (catalytic converter + sensors).
What is the Consumer Assistance Program?
California's CAP offers up to $1,200 toward smog-related repairs for income-qualified vehicle owners. Apply at bar.ca.gov/online_services/cap.