Is your car legal in California?
If your car doesn't pass the inspection for any reason, you cannot legally register your car.
For many people, this may come as quite a shock. Many states have no emissions testing and there are no special hoops to jump through in order to register your vehicle.
ECU-tuned cars won't pass California smog inspection
There are still options for those who want to modify their engines and comply with regulations. As long as the ECU tune is approved through the California Air Resources Board Executive Order, the vehicle will still legally pass the test. There are several companies who offer ECU tunes that comply with the Executive Order.
Will the new measures really help reduce smog?
A common roadblock with emissions testing is that reverting cars back to factory settings by removing the installed software is generally fairly simple.
While this is good for car drivers, it is not good for the state of California, as drivers can simply uninstall the ECU tune in order to pass their emissions testing and reinstall the ECU tune immediately after.
There is little that can currently be done to avoid this scenario, but Europe is working towards making the smog emissions rules more difficult to outsmart. They have proposed reducing 1990-level CO2 emissions by 55% by 2030 and are looking to stop the manufacture of internal-combustion engines by 2035 as reported by Motor Authority.