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 Controls
These controls direct the flow of air from an air pump to either the exhaust manifold, the catalytic converter, or the atmosphere. On all models, a pair of solenoid valves control vacuum flow which operates a Thermactor Air Valve assembly. These valves are called the Thermactor Air By-Pass (TAB) and Thermactor Air Diverter (TAD) valves.
In normal operation, the air is injected in the catalytic converter to improve reduction of emissions. When the engine is idling or decelerating for long periods of time, air is diverted to atmosphere. When the engine is first warming, air is injected into the exhaust manifold to help heat exhaust gases before they reach the converter.
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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