Failed smog test fuel tank not holding vacum

76 is the first year for smog yes cat was on all california A bodies. Older than 76 not smoged. So in your case Bill your Voyager and TC get smoged every 2 years. Your Diesel cars are exempt your other 135,000 plus also are exempt IE older than 76. There are rumors that governor MoonBeam may be about to exempt all cars older than 79.