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Home >> Chevrolet >> 1987 >> Astro Van M L4-151 2.5L >> Repair and Diagnosis >> Powertrain Management >> Emission Control Systems >> Air Injection >> Description and Operation >> Except Electronically Controlled System >> System Description
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System Description

Fig. 1 Air Injection Reaction (AIR) system schematic:





The air injection system delivers filtered fresh air into the engine exhaust stream just after exhaust gasses leave the combustion chamber, Fig. 1. Exhaust gasses react with oxygen in the air, continuing the combustion process and reducing HC and CO emission levels. Air flow within the system is controlled by manifold vacuum operated valves. AIR is used on engines that are not equipped with electronic fuel control systems.