Intake problems - 2002 S60

[lotuscaterham20]

I have a '02 Volvo S60 with the b5244s engine (non turbo). The check engine light is on. P0171 and P0068 DTCs show up. When I erase this codes, the light turns off, but after 3-4 starts it comes back on.
This is paired with a weird rattling noise when accelerating at 50/100% throttle at around 2-3k rpm and, when parking, the engine just wants to stall.
Also, when I turn on the A/C, the idle becomes unstable.

I've checked the PCV valve with the glove trick on the oil cap, works well. The vaccum lines seem OK too. I checked the MAP and MAF sensors. The MAP sensor is giving weird readings. At full throttle (while driving) it just outputs 2-3V, except of the usual 4-4.5V.
This is making me think there is either a problem in the intake (maybe the throttle body not opening fully?) or the MAF is giving a wrong signal. I want to clean the throttle body but it's a Marelli, and I've been advised to not touch it with a ten foot pole as they are delicate.
The car feels good while driving, so I don't have any idea of what could it be.

Has anyone had this codes before? Any advise? Should I risk cleaning the throttle body?

[jonesg]

people tend to get rid of it in favor of the updated Bosch throttle body.