The rule is any USED vehicle which is equipped with the necessary Federal Emission Components (these are the smog parts your Toyota Tacoma was eqipped with when it left the factory) is eligible for California registration as long as the vehicle's exhaust emissions fall within California's limits and the vehicle's emission system has not been tampered with. This applies to used vehicles only. If your Toyota Tacoma was brand new (2014 model and less than 7000 miles on it) and you wanted to bring it to California, you'd need to make sure it was California emissions certified. The under hood emissions label would indicate whether it was or was not.
