OK, I'll throw my 2 quid in! If your tech friend has a DRBII (Factory scan tool) have him do a minimum air flow test-I'll bet you some (whatever you eat for breakfast where you are)) that it'll FAIL! Good news, all you need to do is an induction/fuel injection service. Don't waste your money with junk from the parts store-use a 2901 kit from BG. One can through the fuel rail, one through the induction system (not a vacuum port-a fogger please), and some 44K in the tank. make sure when you put the tank additive in that you fill the tank and drive that first tank down as far as possible. the longer it stays in at that treat ratio, the better clean up it will do. And yeah, I'd check the vacuum circuits too, but you're probably gonna find the PCV system hoses clogged or broken. Please save yourself some misery and don't use regular tubing-go buy the factory PCV harness. Look at the small one that runs to the back of the engine-it may look fine, but it also may be clogged up with goop. Yes,GOOP! Also becareful with the grommets, they mat be brittle! Good luck!