EGR Valves are well known for getting clogged up with carbon often blocking or sticking!
Did you know that the Turbo also gets clogged the same way and impairs its operation?
In Variable Vanes Turbos (VNT) the carbon build up causes desired boost pressures not being met properly, causing poor air fuel ratios which increases the soot produced during combustion, so the problem accelerates itself.
Terraclean have produced a tool that can clean the full system including EGR, Connecting pipework, EGR Cooler and the Turbo restoring the proper function of all the components, it is advised to clean the full system because just cleaning the egr does not give a lasting result as the soot will build back up quickly.