2002 Audi A4 Idle problem

Its a 1.9 tdi 130bhp 5peed and yesterday it began ticking over at just under 1000rpm and now its juddering when ticking over and its hard to put into 1st gear and reverse since its ticking over so high. I have heard that it could be injectors as it is a common problem. Any ideas what it could be? Will it be expensive

Could be a number of things. Air flow meter, injectors, a couple of sensors perhaps?

Price depends on what it is exactly and how quickly it's found.

Nothing is cheap these days, and Audi parts are no exception.

Tickover really shouldn't affect your ability to select gears, as the clutch is depressed and drive through the gearbox is removed. Maybe the clutch is on it's way out?