2009 MKV GTI 2.0t TSI 95k miles. few days ago car starts getting irregular idle and cuts in boost/acceleration. CEL had come on because of it so i took it to my dealer since they offer free diagnostics. they run it and tell me my PCV is going bad along with my DV (older diaphragm revision) so i buy the newest revision PCV and a rev-d DV thinking problems will be solved. come home and install only to find the leak still exists. try the oil cap test while engine is running and its hard to remove and engine wants to stall out right away once its off. same with the dipstick. next check i try the MAF thinking it may be a culprit. unplug the MAF while engine is running and the idle smooths out and sounds great. plug it back in and goes back to irregular idle. so i take the MAF out and clean it and try again, nothing. try a new MAF and still same issue. checked all my vacuum hoses and fittings made sure they are all connected and sealed up and it all checks out. is there anything else im not thinking of? only thing that comes to mind is maybe i somehow bought a faulty PCV? or? need some advice please!