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.
EGR System: Description
The Exhaust Gas Recirculation (EGR) system is designed to lower the burning temperature of gases in the combustion chamber, thereby reducing formation of NOx. A metered amount of exhaust gas is introduced at the intake manifold to dilute the air/fuel mixture to lower combustion temperatures.
The EGR system consists of vacuum amplifier, 2 EGR control valves (except Calif. M/T uses 1), 2 water thermo switches on Federal (1 on Calif. A/T), water thermo valve on Calif. M/T (2 with A/T), engine speed switch and EGR solenoid valve on Calif. models and diaphragm 3-way valve on Calif. M/T models.
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.