hi there im new to this site and audi ownership ive got a 2000 w reg a4 turbo it has a few little problems with running at the mo it had been sitting for 5 months when i got it it starts well ticks over good to but feels like a misfire under 3k in most gears also when driving it hard the car has a bad flat spot like running out of petrol at 4k but then picks back up at just under 5k i have put a new set of plugs in but no change can anyone help with wot it mite be ?

Many thanks big--jayt