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 - Gasoline: Description
The Exhaust Gas Recirculation (EGR) system recirculates exhaust gases into the combustion chamber to reduce combustion temperatures. The reduction in temperature acts to reduce Oxides of Nitrogen (NOx) emissions. On all models except Maxima, 200SX SE, 300ZX and 300ZX Turbo, the system consists of an EGR control valve, Thermal Vacuum Valve (TVV), Backpressure Transducer Valve (BPTV), and various connecting hoses and tubes.
On Maxima, 200SX SE, 300ZX and 300ZX Turbo, the EGR system is controlled by the Electronic Concentrated Engine Control System (ECCS) control unit. The system consists of EGR Control Valve, EGR Control Solenoid Valve, Throttle Valve Switch, Cylinder Head Temperature Switch and Crank Angle Switch.
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.