I have a flashing glow plug light come on for last few weeks and car goes in limp mode when it is on. It goes off when I restart the car and comes back on after some times. Some times it doesnt appear for days and sometimes it comes on after few minutes. I have noticed it mainly comes on during cold and wet weather. The car is usually shaking in the morning and I have seen the water levels go down more quicker than usual. I have run a diagnostic and the code is P046C which apparently is EGR related issue.
Any advise on what this could be and what would be the best way of fixing it? I have been told that cleaning the EGR an fix it? And have been quoted £50 for EGR clean if its at front of engine and significantly more if its at the back. Do I need to clean the unit or just get it cleaned and what are rough costs of replacing it?