forbidance

Just got the 95 mustang running found out my firing order isn't the HO but the no-HO Firing order , anyways got the timing set to 10 deg and went to check my codes now I know I have EGR codes cause last owner Botched the EGR Stuff so I put a EGR Plate on and the Exhaust plugs in Heads. But I got 2 codes one is a ,10 - Cylinder #1 Failed Cylinder Balance Test The other is a, 212 - Loss of IDM (Ignition Diagnostic Monitor) input to EEC or SPOUT circuit grounded. I have checked compression in cyl. 1 and its good,also i moved spark plug and wire to another cyl. to see if code changed to that cyl. and it didn't, I also checked for 12v on injector and Pulse also i heard the injector ticking like it should. So im confused as to what is causing this, I havent really worried about the 212 code yet. Any Ideas?