34, 44, and 94 are all vacuum related. 34 EGR vacuum and 44 and 94 are thermactor vacuum. My guess is that you don't have a vacuum line going from the intake to the vacuum tree that kind of floats on the passenger side of the block.
56 and 66 are MAF sensor related. One is saying the MAF is above maximum voltage and the other is saying that it's below minimum voltage. I would check the wiring in that area.
You may also want to check the wiring to the solenoids mounted on the back side of the passenger side strut tower. Those are what control the vacuum going to the EGR and thermactor system.
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351W 89 Mustang GT Convertible