Hoping for a little further direction on a rough idle issue I have been having. So, my A3 has a a little rough idle for a little while, nothing too bad but you definitely notice it. In idle, it would consistently and slowly rev up to about 1400 rpms and then drop to about 800 rpms. It would just do this in idle over and over again. After doing a little research I was leaning towards a MAF sensor, which upon taking the car to Auto Zone to have the engine light checked, was confirmed. After doing a little more research, I decided to change the PCV valve as well. Reading up on a few different things, I’ve used a few different fault isolation techniques. I notice that the Oil cap was extremely difficult to remove with the engine running which told me bad PCV. However upon replacement, not only was there no change, the rough idle seemed worse. Replacing the MAF sensor and resetting engine light did nothing as well. I know for sure that the PCV valve that was remove was bad as I took apart the diaphragm and noticed the rubber was cracked and deteriorated. I went ahead and replaced the engine coils and spark plugs as well with no change to the idle. I m stuck now on what the problem could be. If it’s a vacuum leak, I don’t even know where to start to look. As of now the idle is pretty bad. Has anyone had an instance in which they replace a bad PCV valve or MAF sensor with no change to a rough idle? Has any used a PCV delete kit? How do I even begin to find a vacuum leak? I would appreciate any help or suggestions on how to proceed. Thank you.