intermittent limp mode-lumpy idle, decided to have a day on the engine! turbo off, cleaned and replaced. egr valve off, cleaned and replaced. inlet manifold off and swirl flaps cleaned and replaced. inlet vacuum actuator replaced! 5 hours but the end result was worth it! no lumpy idle, no limp mode, power delivery a lot smoother. so all in all a great result, couldn't have done it without the knowledge of the people on here!