air box?

[rwellfair]

Still having probs with my 1.8t avent.. seems like its lost alot of power in lower gears and is rumbbling after 4,000rpm ect strting to play up alot now but some 1 said it sounds like teh symtoms of an airbox problem? and when sat still in it after about 20 odd seconds teh revs jump up a small bit then drop down and it very nerly cuts out? help plzzzzzzzzzzz

 

[Turkster]

have you looked at your MAF ?

 

[AU01 A4]

get it scaned first to see if they are any fault codes
it may been the crank breather valve or/and pressure reg valve