I have a 2006 Forester. When accelerating the engine bogs below 2500 rpm and doesn't pull cleanly. It's rather like fuel starvation, but suspect it is more likely a sensor is dirty or malfunctioning. The problem is a bit intermittent and some days worse than others. If anyone else has suffered something similar or can suggest where to start looking, then I'd be grateful for your input!? Cheers.

Had hesitation in my NA Impreza at around 2k revs, cleaned maf sensor and throttle body sorted it out. 

Cheers Jamie, I'll do the same and see if it help.