Puzzled about power loss

I posted something similar in the introduction section but would be better use here. I have a 2000 octy 1.9 tdi agr after a few months lying dead got her back on the road and the 109 relay packed in sorted that then all of a sudden no power disconnected egr system and bought a delete kit from darkside developments looks the job I have to say still the same so the boost solenoid was ticking away like mad changed that along with the vacuum pipes took me a while to figure out where they plumbed but found a diagram online still no power then I stumble across this site found some info on the maf and disconnected it and it ran slightly better!! Got a new one and the crime was solved ran like new!!!