Why the EGR carbons up
The EGR valve recirculates a portion of exhaust gas back into the intake to reduce emissions. Over time, soot and oil vapour bake onto the valve, the cooler and the intake tract. Eventually the valve stops sealing or stops opening, the car logs a fault and runs poorly.
Cleaning the valve restores normal operation in the majority of cases. Where the valve motor or position sensor is damaged, replacement is the right call and we will say so.

