Every California smog check term and question, plainly defined
Do modified or performance vehicles pass California smog?
A modified or performance vehicle can pass California smog only if every emission-related component carries a valid CARB Executive Order (EO) number. Parts without an EO cause an automatic visual inspection failure, regardless of tailpipe results.
CARB EO numbers are issued per part, per vehicle application — the correct EO must match the installed part to that specific vehicle's year/make/model
Common modified-vehicle fails: cold-air intakes without EO, catback exhausts replacing catalyst sections, ECU tunes without EO certification
Aftermarket catalytic converters must be CARB-compliant for the specific vehicle — aftermarket cats without EO are an automatic fail
Engine swaps require the donor engine to be the same year or newer than the vehicle being smogged, and all emissions equipment intact
BAR Referee program handles vehicles with complex modification situations that a standard STAR station cannot certify
OBD-II scan reveals the presence of aftermarket tunes that may have altered fuel/spark/EVAP calibrations
Per CARB Executive Order certification database and BAR visual inspection protocol.