To remove the inlet manifold you will need a 10mm socket for the top 8 bolts which are captive, an 11mm socket for the bottom nuts x 4 and one bolt, unclip the connection to the MAP sensor on the left hand side of the manifold looking at it from the front of the car, undo the egr circlip joining the egr and the exhaust pipe, remove the egr hose, and the intercooler hose, once you have the manifold off the car remove the MAP sensor from the side of the manifold 10mm bolts clean the MAP with a rag sprayed with some carb cleaner, remove all the rubber seals from the manifold these can be wiped clean and re-used after to have cleaned out the manifold, clean it using oven cleaner sprayed inside and left for at least an hour, jet wash out if you can if not try and take it to the local jet wash place that have sprung up all over Britain I am sure they will clean it out for you for £5.
Refit all rubber seals once dried out, fit clean MAP sensor refit to the car along with your EGR bypass once it is all back together give it a Italian tune up. I have all the photo's of said job I must do an how when I get time
