No power
 

Hi all Iam new to this I've got a audi a4 06 1.8t s line convertable the problem is that it will rev fine hold the revs when I drive it there' no power it' not the clutch I've changed I think it' the egr valve because the simular thing happens to my partner audi a4 2.5 tdi the only diffeence hers is a desiel please help