To do this job the intake manifold needs to be removed. At this point we usually advise to clean out the intake runners in the head. These engines have carbon buildup issues due to location of the fuel injectors. After 100k the amount of carbon buildup on valves could be enough to cause misfires, engine idling poorly, and low power.
These engines are in the VW GTI mk5 and 6,Jetta mk 5 and 6, Passat B6, CC 2009-2015, EOS 2008-2014, Tiguan 2009-2015, Beetle 2012-2015, Audi A3 2008-2014, TT 2008-2014