95 tdi down on power?

[snakemaster]

poped in to a shop come out started the car and the revs went up to 2000 back down , done this twice , and the power is now down 20hp maby more, change the MAF the same, the n75 valve seems ok, intercooler pipe temp sencer ok, put a boost gauge on and reads .8 bar max boost , is there some thing i have over looked  oo its a 1z