Air Injection System

The CCC system uses a 3-way catalytic converter to reduce harmful emissions. The rear half of the converter needs additional oxygen to operate, so the air injection system is designed to supply air to the converter as well as the exhaust manifold.

During warm-up, the system supplies air to the exhaust manifold, which helps to complete combustion in the manifold, and heats the oxygen sensor rapidly. When the sensor has reached operating temperature, air can no longer be supplied to the manifold, since the additional oxygen would "fool" the oxygen sensor, preventing it from determining mixture.

An air switching timer (on Firewall) is used by the CCC to provide air switching. As soon as the engine coolant sensor indicates to the computer that coolant is warm, it starts a 70 second timer. At the end of 70 seconds, a signal is sent to a vacuum solenoid, which allows vacuum to operate the air switching valve. Air is directed "downstream" to the converter. If the engine is warm when started, the 70 second timer is started immediately. See Figure.