پوشیده شدن دریچه گاز EGR از دوده

The diesel intake throttle bound up by the deposits its own position guarantees — it sits exactly where recirculated exhaust soot meets crankcase oil vapour, and the mixture bakes into a paste that stiffens the flap, then sticks it. This is structural, not accidental: the P2413 argument applies, and a valve cleaned without asking why the deposits formed (worn breather, cooked oil, short-trip running) invites the sequel.

The progression is diagnostic in itself: first the position codes report lag (the flap answering slowly), then performance codes (commanded one place, found in another), then the stuck codes — so a lag code is a cleaning appointment offered cheap, and a stuck code is the same appointment after the price went up. Cleaning genuinely works when the flap still moves; a seized spindle or stripped actuator gears need parts.