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What is the Purpose of the EGR Valve?

Model: (Various brands) Various
Part: EGR valve

Video tutorial

The EGR valve is used to reduce nitrogen oxides (NOx): as mentioned in the video, it draws exhaust gases from the exhaust system and brings them back into the intake. The exhaust gases, once reintroduced into the intake, have little oxygen, dilute the air-fuel mixture, lower the combustion temperature, and with lower temperatures, less NOx is formed.

The EGR valve is subject to carbon build-up. If the valve gets stuck closed, the vehicle does not reduce NOx; if it gets stuck open, the car continuously consumes exhaust gases, leading to ignition problems, rough idling, the vehicle not starting, or going into limp mode.

It is possible to clean it with specific spray if it is just caked.

If the actuator (the electrical or mechanical part that moves) is stuck, it needs to be replaced. Physically removing the EGR is illegal for road use: removing it via the ECU is a modification that makes the car non-compliant and exposes us to hefty fines and failure to pass the MOT.


Posted on 21 May 2026 by ScegliAuto


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    • Vari - How much does the labor cost to replace the EGR valve? Read answer

How to Remove the Rear Seat of a Hyundai Tucson?

To remove the rear seat of a Hyundai Tucson, follow these steps. Start by moving the front seats to their most forward position to gain space. Next, locate the release lever on the underside of the rear seat, near the floor. Press this lever down while pulling the seat upwards to unlock it from the anchor pins. Once unlocked, tilt the seat upwards and forwards to remove it from its position. Repeat this process for both sides of the rear seat. Be careful of any electrical cables or components that may be connected to the seat during removal. Once the rear seat is removed, the disassembly is complete.

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by ScegliAuto

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