Your Toyota Tacoma should require a smog check every two years. You might want to contact the DMV at (800) 777-0133 and inquire why your Toyota has needed a smog check three years in a row.
We have heard in the past that if a vehicle on a previous smog test failed as a gross polluter, it would be required to undergo a second smog inspection the following year. The year following becomes the year in which the vehicle requires it's regular biennial inspection and you'll need one more smog test. So technically you end up smogging your car three years in a row.
