hey there - new to the forum. Just bought an 06 2.0T A4 Avante - love it. Having a slight hesitation issue from 0-50. Did some reading and maybe the PCV valve. Bought the part at AA Auto - changed it tonight. Hesitation seems to go away but in park at idle the engine shakes like it is starving for air? Put the old one back on - no issue? Should i stick with dealer parts - are they that finicky? Is is something else?