Starting today, the California Smog Check Program will begin testing vehicles to ensure their vehicle is running either an OEM or California Air Resources Board-approved engine software tune.
The ‘Frequently Asked Questions’ section of the California Smog Check website was updated last week to include a new amendment indicating the test will now include an ECU software test to ensure the vehicle owner has not installed an illegal engine tune.
“Beginning July 19, 2021, vehicles with software not provided by the original equipment manufacturer (OEM) or approved through a California Air Resources Board (CARB) Executive Order (EO) will fail Smog Check,” the FAQ section now says. “Before your vehicle will pass a Smog Check, you must have the vehicle’s software restored to the OEM or EO approved software version. Once the software is restored, have your vehicle reinspected by a licensed Smog Check station. Note that vehicles initially directed to a STAR or Referee station must return to the same station type to complete the inspection process.”
With this change, Smog Check and CARB hope to reduce vehicle emissions in the state of California by doing away with vehicle engine tunes. Engine tunes are often applied to modern-day turbocharged vehicles to help increase horsepower and torque output without having to make any parts changes or physical modifications to the engine components themselves. These engine tunes typically increase boost pressure and changing the air/fuel mixture.
Some manufacturers have begun to take action against aftermarket engine tunes as well. General Motors, for example, has begun using encrypted engine control units for cybersecurity reasons – locking tuners out of its engines in the process. The new C8 Corvette Stingray has one of these encrypted ECUs and, as a result, can only be tuned in very limited ways.