Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Air Injection System: Description
The air management system consists of the following sub-systems: Air Injection, Secondary Air Control, Air Induction and By-Pass Air Control. The air injection system controls CO, HC and NOx emissions by injecting secondary air into the exhaust system to cause further burning of exhaust gases. System consists of an air pump, 2 check valves, an air control valve, relief solenoid valve, switching solenoid valve, heat hazard sensor and catalytic converters.
Air is drawn from the clean side of the air cleaner by the air pump and directed to the air control valve under pressure. From the air control valve, secondary air is directed (by the switching solenoid valve) "downstream" to the pellet converter or "upstream" to the exhaust port.
The air induction system brings air into the engine for combustion functions. The system consists of an air cleaner, air flow meter, air funnel, throttle chamber, dynamic chamber and intake manifold.
The secondary air control system contains 2 check valves to prevent exhaust gas from leaking back into the air pump. The switching solenoid valve directs secondary air through the air control valve "downstream" and/or "upstream", based upon engine temperature, manifold vacuum and engine speed.
The By-Pass Air Control System (BAC) controls the amount of by-pass air to maintain idling speed. System is controlled by a air by-pass solenoid valve, relief solenoid valve, split air solenoid valve and port air solenoid valve.
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.
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