First EPA emissions on cars

Positive crankcase ventilation (PCV) was introduced in 1963 on most cars to counter the growing smog problem, mainly in California. Prior to PCV, crankcase overpressure -- an inevitable problem in a gas-burning engine -- was relieved by a simple "down tube," a bit of rubber or plastic that led from a fitting in a valve cover down to exit openly under the car. PCV countered the emissions of oil-soaked compression blow-by using a one-way valve fitted in a tube that fed the blow-by into the engine's intake manifold. The vaporous oil and exhaust was thus burned in the combustion chambers and exhausted more cleanly into the atmosphere.

This was followed by Air injection in the late 60's, and catalysts in 1975. Engines of the time were also detuned to reduce certain emissions. Starting in the mid-1980's, fuel injection and computer controls made it possible to regain the power that had been "lost" in the opinions of some, and cars now have more power (and get better mileage) than ever, given their size and weight. As someone who drove alot of the cars of the 60's and 70's, I can tell you, you don't know how lucky you are. They weren't that great. also if I'm not too mistaken, the switch from leaded gas could also be considered a EPA emission law.