a standard fiesta turbo can come with either ecu mate,ur best off looking at whats in ur car by either droping the ecu down and looking at whats written onit ,or by looking at what map sensor is fitted as the ofac uses the same as the xr2i and 3i but the ofab uses the webar marelli 1.and as for the chip it has to be ofab for ofab and ofac for ofac.