1984 Toyota 4Runner BaseFACTORY OEM SERVICE PROCEDURE

Air Injection System: Description

Air injection with feedback system is used to reduce hydrocarbon (HC) and carbon monoxide (CO) emissions. Fresh air is injected at exhaust ports, allowing exhaust gases to continue burning as they exit through the exhaust system. An air pump provides fresh air under pressure to be injected in exhaust ports. A computer control system determines when the air should be injected.

Components include air pump, air cleaner, electric air control valve (EACV), check valve, vacuum control switch (VCS), three-way catalytic converter (TWC), 2 thermo switches, and oxygen sensor.

Factory Service Tools

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:

  • β€’ You smell fuel, burning insulation, or see smoke.
  • β€’ Brakes feel soft, pull hard to one side, or make grinding noises.
  • β€’ The engine overheats, stalls repeatedly, or misfires under load.
  • β€’ You are missing required tools, torque specs, or safe lifting equipment.
  • β€’ You are not confident in the next step or safety outcome.

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