So last night car was idling rough. Andrei took me step by step on how to diagnose the problem. Took the valve cover off and it had a hissing noise coming from it. Put my finger over it and it helped and the car was running better. As a temporary fix I put a piece of duct tape over it so I can get it to the dealership. Well that didn't last long. Car started to smoke really bad. Could it still be the pcv valve?