2007 s80 t6

[Getschwifty121]

I just bought a 2007 s80 3.2l that had been sitting for about 1-2 years and its been throwing these codes p0300, p0302, p0306, p0171 and p003f.

I have already replaced battery, engine upper left (pax) motor mount, spark plugs, and ignition coils.

When it starts the first time there is no real issues but if I turn it off and start again it takes 1 or 2 tries to get it to start. When it does start back up there is issues with throttle response and it has a rough idle with a squeal/ whistle during idle and when idling in gear. It goes away when driving and rpms over 1000. The idle levels out after 2 minutes or so and the squealing goes away if I pull the dip stick out so i am assuming its the PCV, would this also create the misfire and running lean? Also noticed it gets hot fast but no over heating lights yet. Fan turns on within 5-10 minutes of idling.

Planning on replacing the PCV, serpentine belt, VVT, oil change, air filter and cleaning the MAF. Is there anything else I should look at to troubleshoot?

Thanks in advance

[June]

The squeal is the PCV box it's common on those, but it's on top of the engine, I do believe. I suggest looking at the fuel injectors for the misfire and hard starting. You did say the car sat for years. June