what was the first year auto maker put catalytic converters on cars.
I believe that the first ones were on GM cars in 1975. There may have been some cars built in 1974 as 1975 models that had them. They were not legislated, but the tough emission standards coming into force made it necessary for most cars.
Model year 1975.
FYI…Some 1974 models were equipped with catalytic converters. I bought a new 1974 Monte Carlo in early '74. It started having problems on our first trip home in the summer. The Chevy dealer towed us in and here is what they found: New HEI distributor had no silicon under the ignition module so it burned out. Spark plugs were gapped at .035 instead of .060. The spark plug wires were the original OEM non-HEI variety which suffered burns. Vehicle was equipped with catalytic converter which required unleaded fuel but no sticker. Supplies of unleaded were mostly non-existent. I had to go through a Chevy arbitrator and was given a refund. They seemed pleased to get their hands on the vehicle and all of the paperwork from the dealerships.
My mother bought a 74 Monte Carlo S in 74, all california factory, 350V8 4bbl,and owned it up until 91,it ran perfect for about 6 months then also started giving her problems with starting up.It would have to be warmed up good like any old carburetor vehicle would have to when cold before driving off and it would be fine,but if she parked it someplace after long drive or even close by and tuned it off,it would refuse to start, would flood real bad and you would have to let it sit for few hours before it would finally catch and start very cold blooded car.It would be put in the shop and it always seem to be something to do with the distributor spark plugs,carburetor was always adjusted and good,but once out of the shop it would not last long and would give her trouble again seems to be a common issue with these 70’s chevy’s if kept all original not the best and not dependable at times but can be if completely restored it will cost you big $$ though.
The catalytic convertor was actually invented by GM and shared with other automakers to help clean up the air. GM pretty much installed cats across the board in '75. They were crude bead-type simple 2-way cats. We used to bust the beads out by jamming a bar into the opening to knock the beads out to improve the flow. I even passed a smog test with an empty convertor.
Today’s 3-way cats flow much better and clean the exhaust much better. There is no real penalty to performance by using them. And stiff fines are levied for fiddling with them now, although I don’t see any agency actively enforcing these laws.
According to Wikipedia, cat converters were invented around 1950, by a French engineer living in the U.S. who founded a company called Oxy-Catalyst to manufacture them, for use on refinery smokestacks. Development for automobiles came in the years immediately following. They first became widespread in automobiles in 1975.