Hi
My car appears to get this P0401 code with the engine light on the dash, only happens on very light throttle, EGR valve cleaned out, vaccum pipes in good condition, no other problematic symptoms
with the car, no limp mode, runs a little lumpy just off tickover, pulls strongly, good mpg. Anybody got any ideas what may cause this ?..Octavia 2.0tdi 16v 2005 1ze BKD

Thanks