it is hard to suggest something when you have a professional mechanic is by your side... If i were doing it myself, i would have checked all the connections, especially MAF, i would look to see if there is no vacuum leak, like a displaced tubing... the codes that you are getting, could be secondary to the main issue, that is probably a misplaced connector...

can you retrace your (your mechanic's) steps to see if every wire is plugged in without any loose wires/plugs...