What next? TD5 power loss?

Further to earlier thread I'm a little bit further on with diagnosing my power loss problem, and am looking for the next steps?

Model: TD5 2003 110 Double Cab with 140k on clock.

Symptoms: Very sluggish when cold (no smoke), absolutely no 'pull' whatsoever. Once warm (circa 15-20 mins) intermittently pulls very well. Once it starts to run correctly, seems to be ok even if switched off for awhile etc. Once warm, it seems only to start pulling after the engine has gone from full power to tickover, i.e. at a junction or when coming out of a 30mph zone etc? Drove 200 mile round trip with long break in same day. Both times ran like a dream after initial 'warm-up' issue. Has 'once or twice' run properly when not up to temperature, giving me the impression that it is not temp related, rather something that is 'sticking' intermittently??

Done so far:

Checked the waste gate valve is free.
Fitted an EGR blanking kit.

New fuel control valve - done at garage due to fuel leak
New air filter - garage as part of service
New fuel filter - garage as part of - service
New oil filter - garage as part of service

Note: A snorkel is fitted which I can remove/check and plan to do so as a matter of course.

Question is, what's next and in what order ie. simplest/cheapest/most likely first.

Thanks for any help.....

get the codes read , check MAF and MAP sensors . and try disconecting the temp sensor and see if its any better

Defcrazy, all sounds like a good idea, but probably need a bit more info.... I'm not at home at the moment so will wait till I get back (10 or so days from now) and will then scour the Haynes manual etc. to get a better idea of where the sensors are exactly and what to check for and then post again. Thanks for prompt response. F

the MAF is between the air filter box and the intake hose to the turbo .the MAP is on the intake manifold (top middle held by two bolts). both could be cleaned with brake cleaner or similar and see if it makes a diffrence

Great stuff, thanks Defcrazy - will give it a go.

FIXED !!!!!!!!!! so happy! Goes like stink from cold..... !! Removed the MAF looked ok and replaced. Disconnected MAP/IAT took for run... No change. Removed it from manifold - it was oily and greasy so WD'd and blew clean with air line. Did the same for MAF and AAP. Took for another run..... Bingo!!! Thanx to all for help.... Especially to DEFCRAZY!!! saved a big bill I'd imagine, and great sense of achievement!!! Fraser