Engine Change Guidelines
An “engine change” is the installation of an engine that is different from the one which was originally installed in the vehicle and does not qualify as a “replacement engine”.
Engine replacements include:
- A new, rebuilt, remanufactured, or used engine of the same make, number of cylinders, and engine family (test group) as the original engine with the original emission controls reinstalled;
- An engine which matches a configuration offered by the manufacturer for that year, make and model of vehicle, and the appropriate emission controls for the installed engine, and chassis components are present and connected.
The replacement of older engines with newer, more technologically advanced engines required an update to the guidelines to maintain air quality, while also providing a reasonable pathway for engine changes on California vehicles.
The State of California Engine Change Guidelines are contained within the BAR Smog Check Reference Guide, which is located on BAR’s website at Smog Check Reference Guide (see Appendix E).
Engine changes can present challenges and potential problems for vehicle owners, inspectors, and technicians if not done correctly. Replacing the original engine, transmission, and emission control system with an identical configuration, or using a CARB exempted engine package will help to eliminate challenges and potential problems.
All vehicles with engine changes must pass an initial inspection at a Referee Center , and must have a BAR Referee label affixed to the vehicle inside the engine compartment. After the initial Referee inspection, future Smog Check inspections can be obtained at a regular Smog Check station. To make an appointment, consumers may contact the Referee at (800) 622-7733. Engine replacements are not required to be inspected at the BAR Referee. Having the VIN of the donor vehicle provided at the initial Referee appointment will simplify the process.
State and Federal anti-tampering laws specifically prohibit any modification to the vehicle's original emission control system configuration as certified by the manufacturer (California Vehicle Code Section 27156 and Title 16, Section 3362.1 of the California Code of Regulations).
The initial Referee inspection will be based on the Smog Check requirements of the engine donor vehicle. Subsequent inspections at a non-Referee Smog Check station will be based on the BAR Referee label affixed inside the engine compartment.
Smog Check frequency requirements do not change after a vehicle has undergone an engine change. For more information, refer to BAR's Smog Check Requirements by Vehicle Type table.