[Cushionmonkey]

Sorry to everyone if this has been covered before and for the long post but my poor car isn't well it seems. I have a 2002 S60 D5 163 on 160,000 miles, most of which are long motorway journeys. I've owned the car 10 years and it has a FSH with all filters replaced yearly. She did have No.4 injector replaced 2 years ago but it was of the same type also a new clutch and DMF. When accelerating the engine feels rough and lacking in power. The turbo kicks in fine with no noise but the engine just feels rough, almost struggling and with some cavitation/vibration, especially when accelerating say from 50 to 70, hubs seem to be fine though and no distinct engine noises. I just can't seem put my finger on the problem. Is there anything I could be missing that I need to maybe look at or check? I've cleaned the plenum chamber part way, I can't do the rest till I find a torque wrench however. Also since the injector replacement it's had injector knock on accelerating under load, but on speaking to volvo service they advised this can't be removed, which is a shame as it's very annoying. The air box housing the filter also has also suffered from the heat distortion issue it seems. I know this isn't much to go on but I just wondered if there is anything I've missed or I can try, clean etc before paying to check for any error codes or faults.
Any help appreciated, thanks in advance.