Hi I have a mk5 golf gti o5 plate it was fine then I was told the rocker cover gasket was going so I had it change after it was changed the car revs would go up to
20 then back down to 10 and carry doing
This and iding very poor so change the pcv valve and the car carried on iding poor so I changed the air mass meter but it's still iding poor and the revs go up and down slowly and help would be nice cheers