Guides

The Smog Check Referee and modified cars

The Referee is BAR's program for inspections a regular Smog Check station can't settle, including vehicles modified with aftermarket parts.

When you may need the Referee

  • You disagree with a failed result after having the car diagnosed, and still believe it should pass.
  • Your vehicle is modified or has an engine change. The Referee program says that if you modified your vehicle with aftermarket parts, you may be required to have the Smog Check done by a Referee.
  • You were cited for modified emission controls (Vehicle Code 27156) or loud exhaust (27150/27151).
  • A station refuses to inspect the vehicle, or you need help finding a hard-to-find emissions part.

Steps

  1. Have the failure diagnosed first. The Referee program does not diagnose or repair. If your car failed, a licensed Smog Check repair station must diagnose (and repair) it before you contact the Referee.
  2. Have a failed Smog Check on record. An appointment needs a failed inspection in the vehicle history and a reason. A failure shows up the next business day.
  3. Bring the EO paperwork. For EO-exempt parts, keep the EO label on the part and bring a copy of the EO. Modified or non-approved software causes a Smog Check failure, so restore the factory calibration or a CARB-approved version.
  4. Phone appointment, then retest if eligible. The first appointment is a phone call with the Referee about your dispute. The Referee provides retests for eligible consumers.
An EO lets you install the listed part on the listed vehicles. It does not let you skip the inspection, and the car must still pass the Smog Check that applies to it.

Questions

Can the Referee pass a car with a part that has no EO?

Not as an EO-exempt part. Common reasons to fail include being modified with non-approved parts or computer programming. Return the part to stock or replace it with an EO-listed part for your exact vehicle.

Does the Referee inspect motorcycles?

No. The Referee program states it does not perform motorcycle inspections.

I was cited under Vehicle Code 27156. What happens?

The vehicle must pass a complete Referee inspection, which includes checking that the computer programming is not tampered with. The program strongly recommends removing modified equipment or programming before the appointment.

Sources (checked 2026-11-11): BAR, Smog Check; Smog Check Referee program, Services overview, Smog Check results review, Unusual vehicles/engine changes, Citations and noise violations. Fees and procedures change; confirm with the Referee program before your visit.