Vauxhall Vectra wont go above 3000 revs

i believe that the problem you have is down to your maf,mass air flow sensor,it is a common fault on vauxhalls,it can be found on the pipe coming from the airbox,start the car and unplug it while its running,this will put engine management light on as a fault but if the car runs better you have found the problem,i have just done the same to my 1,7 dti astra,i had to buy a new maf sensor,around 40quid,car runs great,hope this works for you.