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 - Diesel: Operation
EGR valve is located on intake manifold. It introduces exhaust gases to incoming fresh air at engine crossover. EPR valve is located between exhaust manifold and exhaust pipe, and is used to increase exhaust backpressure during idle which increases exhaust flow through the EGR system. TPS is located on throttle shaft of injection pump. As throttle is opened, one switch contact opens a circuit and another switch closes a circuit at calibrated throttle angles.
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.