They could try and say the relocated MAF sensor may be causing the issue. What kind of intake are you using? If it is one that keeps the maf in the same spot such as Steed a, Fswerks, or k&n should not be having issues unless there's a leak before the maf sensor.
'14 Fiesta ST
200HP / 263 TQ
SCT Tune & Injen Intake, MBRP Catback
Moderator: Third Generation Ford Focus, DURATEC Ti-VCT GDI Performance Chat & Florida regional section