On 1996 And Newer Cars
For OBD equipped vehicles, the car fails if the MIL is commanded on, if any trouble code is stored, if the MIL does not light with key on and engine off, or if too many monitors are incomplete. Gas cars 1996 to 1999 may have one incomplete monitor. Gas cars 2000 and newer may have only the EVAP monitor incomplete.
BAR says a rule requiring all monitors to be set took effect October 1, 2025, but that the old allowances stay in use while it studies Smog Check data.
The Gas Cap Test
The fuel cap integrity test is done on 1976 to 1995 vehicles with evaporative controls. It has a visual check and a functional check on a cap tester. For vehicles newer than 1995 the functional cap test is not done.
The Low Pressure Fuel Evaporative Test
The Low Pressure Fuel Evaporative Test (LPFET) pressurizes the fuel evaporative system with a BAR certified tester. It is done on 1976 to 1995 vehicles, with exceptions such as two or more working fuel tanks, a single tank over 50 gallons, no filler neck adapter, or a canister and hoses that cannot be reached without taking the car apart.
We could not find the LPFET start date in a BAR or CARB source. BAR rules say LPFET equipment must meet the LPFET Specification dated January 2012. A 2007 blog post gives a different date, but it is not a primary source, so it is not used.
If You Failed
Fix the code first, then drive until the monitors set before going back. Read what happens during a California smog check.
Author Source EEAT Authors · Anthony's Author Page
Sources For This Page
- Smog Check Manual, April 2025, California Bureau of Automotive Repair, read 2026-11-12
- 16 CCR 3340.42.2, OBD Test Failure Criteria, California Bureau of Automotive Repair (via Cornell LII), read 2026-11-12
- 16 CCR 3340.17, Test Equipment, California Bureau of Automotive Repair (via Cornell LII), read 2026-11-12
- New OBD Readiness Monitor Regulations Explained (Fall 2025 newsletter), California Bureau of Automotive Repair, read 2026-11-12