Q: Lack of acceleration lumpy idle doesn't pull away well.

I have recently had some work done on the car at audi where they found oil in the header tank and carbon in the egr valve which they replaced. Since I had it back the idle has become very lumpy and can be worse when the temperature outside is hot. The acceleration is lacking when it comes to motorway speeds and pulling away is sometimes not the best. Also when starting the engine it can have a bit of a judder. Audi took it for a test drive and said that my clutch and flywheel were near to the end cos of it slipping. I then took it to another garage and they said that the clutch is fine about half worn. He mentioned that it may be injector problems. So am wondering what you think and how do I go about diagnosing the fault without spending lots of money. Don't have the engine management light on so a little confused. All I know it's not that nice to drive at the moment. I have a 2 tdi.not the v6.

My car has 107000 miles.
My car has a manual transmission.