Engine Change Guidelines
Engine changes continue to present problems and challenges to car owners and technicians. Our recommendation is to rebuild and reinstall the original engine, transmission, and emission control configuration.
When rebuilding an engine, it must be rebuilt to the original equipment specifications. However, if you do decide to change the engine, these guidelines must be observed to ensure that the vehicle will be eligible for smog certification or registration.
Remember, these are guidelines for performing engine changes - not certification procedures. All exhaust emission controlled vehicles with engine changes must be inspected by an official Referee station and must have a Bureau of Automotive Repair (BAR) Referee label affixed to the doorpost.
Remember also, state and federal anti-tampering laws generally prohibit any modification to the vehicle's original emission control system configuration as certified by the manufacturer. And, Section 3362.1 of the California Code of Regulations prohibits any engine change that degrades the effectiveness of a vehicle's emission control system.
A federal Environmental Protection Agency (EPA) certified (federal or 49-state) engine cannot be used in a vehicle that was originally certified for California.
Make sure the engine and emission control configuration on exhaust-controlled vehicles are certified to the year of the vehicle or newer, and to the same or a more stringent new vehicle certification standard.
Don't mix engine and vehicle classifications which will degrade the emissions certification standards. For example, a heavy-duty engine cannot be installed in a light-duty exhaust-controlled chassis even if they have the same displacement. Non-emissions controlled power plants such as industrial or off-road-use-only engines may not be placed in any exhaust-controlled vehicle.
If a computer-controlled engine is installed in a non-computerized vehicle, the "CHECK ENGINE" light, the Original Equipment Manufacturer (OEM) diagnostic link, and all sensors, switches, and wiring harnesses needed to make the system fully functional must also be installed.
Emission Control Configuration
Mixing and matching emission control system components could cause problems and is generally not allowed. Engine and emission control systems must be in an engine-chassis configuration certified by the California Air Resources Board (ARB) or U.S. Environmental Protection Agency (EPA). The engine must meet or exceed the requirements for the year and class of vehicle in which it is installed.
Voiding the vehicle manufacturer's emission warranty is not allowed.
No internal or external engine modifications (cams, pistons, intakes, etc.) may be performed unless the parts are ARB-exempted or EPA-certified for use in the installed engine. Refer to ARB's Aftermarket Parts Database of Executive Orders to search for exempted aftermarket parts.
The installed engine and host chassis must retain all of their original emission control equipment. Diesel-to-gasoline conversions must have all gasoline engine and chassis emission control systems installed (such as fillpipe restrictor, catalytic converter, and evaporative emission system).
These vehicles must pass a complete Smog Check.