Catalytic converters
Here's some information from the dealership data book '75. According to the data book a "catalytic converter...is standard on most models".
https://www.hamtramck-historical.com/images/dealerships/DealershipDataBook/1975/75-Dart_0002.jpg
So looks like '75 is the right answer, for "most" of the '75 models anyway.
In California it used to be a rolling 25 year deal, anything more than 25 years old was exempt. Then they stopped it so that '75 was the last year exempt. I had always thought it stopped there because '76 was when the convertors came out, so you couldn't take a catalytic convertor off a car that came equipped with one. But it looks like I was mistaken! Thanks for the correction @Kern Dog
As a California resident and owner of a '74 model year car with an engine swap that is completely smog exempt, I can assure you that no catalytic converter has to be added to a '73 or later car here. '75 and older are smog exempt in California and do not need to be tested, let alone have anything added.
Here's some information from the dealership data book '75. According to the data book a "catalytic converter...is standard on most models".
https://www.hamtramck-historical.com/images/dealerships/DealershipDataBook/1975/75-Dart_0002.jpg
So looks like '75 is the right answer, for "most" of the '75 models anyway.
In California it used to be a rolling 25 year deal, anything more than 25 years old was exempt. Then they stopped it so that '75 was the last year exempt. I had always thought it stopped there because '76 was when the convertors came out, so you couldn't take a catalytic convertor off a car that came equipped with one. But it looks like I was mistaken! Thanks for the correction @Kern Dog
As a California resident and owner of a '74 model year car with an engine swap that is completely smog exempt, I can assure you that no catalytic converter has to be added to a '73 or later car here. '75 and older are smog exempt in California and do not need to be tested, let alone have anything added.