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.
THERMACTOR Air (Reed) Check Valve (THERMACTOR II Only)
When pressure in the exhaust manifold is more than the pressure in the air cleaner (positive pressure), the air inlet valve closes. When pressure is less in the exhaust manifold than in the air cleaner (negative pressure), the valve opens. At this point, air is drawn into the exhaust manifold where it reduces hydrocarbon and carbon monoxide emissions by continuing the combustion of unburned gases in the same manner as an air pump system. This opening and closing is a normal pattern established by exhaust gas pulses created by the combustion process.
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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