Three emission control systems are found on 1967 through 1969 Camaros:
* The Air Injector Reactor (AIR) system pumped air into the exhaust manifold(s) to help complete the combustion process. The AIR system consisted of the air injection pump (aka smog pump), a fuel mixture control valve (1967) or an air diverter valve (1968-9), check valves, air manifold assembly, and air injection tubes (one per cylinder).
* The Controlled Combustion System (CCS) was introduced in 1968 and was used on cars that did not receive the AIR system. CCS improved combustion efficiency via recalibrated carburetor and distributor settings and higher operating temperatures (compared to 1967). The higher operating temperatures were accomplished by using a 195°F coolant thermostat (instead of 180°F) and the use of a thermostatically controlled air cleaner (ThermAC). The ThermAC system was designed to warm intake air to 100°F when underhood temperatures were less than 100°F. It consisted of a damper door mounted on the snorkel of the air cleaner which directed warm air from a heat stove on the exhaust manifold into the air cleaner.
* The Positive Crankcase Ventilation (PCV) system utilized manifold vacuum to draw crankcase vapors into the engine to be burned. Filtered air was drawn through the engine, through the PCV valve, and into the intake manifold.
In 1967 (as in 1966), emissions equipment was required only on cars sold in California. The California cars were fitted with an AIR system (Regular Production Option (RPO) K19), and the PCV system (RPO K24). All engines equipped with K19 had unique engine codes due to the required holes in the exhaust manifold(s). Also, the L26 (230 ci L6) engines with K19 used a different distributor and the L30 (327 / 275hp) engines with K19 had a different initial timing. Note that smog equipment was not required on cars built in California but intended for sale in other states.
In 1968 and 1969, the California and federal emissions requirements were the same and all cars were built to the same 50-state standard. The AIR system was installed on all L6 cars with manual transmissions, all small blocks with manual transmissions, and all Camaros with big blocks. (Chevelles and full-size cars with the 396/325hp engine and TH400 transmission were the only 68-69 big block cars to not have smog pumps.) Only the automatic L6 and automatic small block Camaros did not have smog pumps, instead they had the simpler Controlled Combustion System. Generally speaking, an automatic car required less aggressive emission control than a manual transmission car because the engine load (and carburetor fuel metering consistency) was more stable and predictable.
In 1968, vehicles exported to Canada and other countries did not require the AIR system. RPO KD1 was used to delete the system (if it would have been so equipped otherwise) and 1/4"-18 NPSF straight pipe thread plugs were installed in the manifolds. It is unknown if a credit was issued on the Canadian window stickers for this delete. The Controlled Combustion System was still installed on the exported L6 automatic and small block automatic cars.
In 1969, Canadian cars used the same emission controls as U.S. cars.