It's a subi 2.5l flat 4......you can take the darned engine out and fix it on the diningroom table!

The headgasket would, however, explain the low coolant and the CEL.

Just FYI, OBD II codes (anything 1996 or later) are universal, and you don't need a Ford code reader to read ford codes, and the codes are universal. Doesn't matter if it's the scantron at AutoZone or the $20K diagnostic computer at the local auto shop, they're all reading the same failure codes.

The difference is in how deep the diagnostics can get, whether it's just reading codes or allowing the mech to do a live monitor diagnosis.