I've had 1999(V) 1.8t quattro sport, engine code AJL, for 3 years now and over time have noticed a drop in power. It has been regularly serviced, new plugs and stuff. It is pretty standard apart from a Pipercross panel filter. I have noticed some oil in the vacuum pipe leading to the inlet manifold and air intake. Something I have noticed is the kick when the turbo kicks in is hardly noticable anymore but you can still hear the turbo sucking air in. Any pointers or advice would be great as I'm getting annoyed at being overtaken by ****** Vauxhalls