I have a 2006 Jetta TDI which began having intermittent CEL from open cct on one of the GP cylinders (always same one). All components have been replaced (plugs, wiring harness, module). It has gone from occurring once every few months to roughly every other car start based on the # of instances visible on scan. Shop is recommending I replace ECU as all other options have been exhausted according to them. I find it very hard to imagine that my ECU is functioning fine but causing this particular “glitch.” Seems much more likely to me there is a wiring issue elsewhere. Have not seen any evidence of a hard start or white smoke, even during cold winters. Getting to the point though where if I look at the check engine light in my dash one more time I run the risk of having an aneurysm.

Anyone have potential insight?