The air suction system uses exhaust gas pulses to draw air into the exhaust manifold (catalytic converter on Corolla, Tercel, and Tercel Wagon) to help to complete oxidation of emissions.

The air suction system on California Corolla, Tercel, and Tercel Wagon models consists of a shutoff valve, a Vacuum Transmitting Valve (VTV), reed valve, and necessary hoses. The Federal Corolla, Tercel, and Tercel Wagon air suction system consists of a reed valve, air filter (if equipped), and hoses. See Figure and Figure .

The air suction system on California Pickup and 4Runner models consists of the Computer Controlled Emission (CCE) system computer, 2 temperature switches, 2 vacuum switches, engine RPM sensor, vehicle speed sensor, oxygen sensor, reed valve, electronic air control valve, and resonator. See Figure. Federal Pickup and 4Runner models use a reed valve, Vacuum Control Valve (VCV), Vacuum Transmitting Valve (VTV), Air Switching Valve (ASV), and resonator.

NOTE: The air suction system on California Pickup and 4Runner models is closely tied with the carburetor/fuel feedback control system. See CARBURETOR/FUEL FEEDBACK CONTROL SYSTEM article in the EMISSIONS section, for information and testing of vehicle speed sensor, temperature switches, and oxygen sensor.

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.

Safety Warning

Air Suction System: Description

Use the Manual With the Right Hardware

When to See a Mechanic

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