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
Air injection is used on these models to reduce hydrocarbon (HC) and carbon monoxide (CO) emissions. Fresh air is injected at the exhaust ports, allowing the gases to continue burning as they exit through the exhaust system. An air pump provides fresh air under pressure to be injected in the exhaust ports. A control system determines when the air should be injected.
The control system varies with each model. Major components include air control valve (ACV), air switching valve (ASV), check valve, vacuum transmitting valve (VTV), bimetal vacuum switching valve (BVSV), vacuum switching valve (VSV), vacuum control valve (VCV), catalytic converter temperature sensor and oxygen sensor.
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
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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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