You are going to want to check the codes first. Although on my car the codes haven't really lead to jack.
There are several possible causes for an EGR code failure: the TPS sensor, the MAF sensor, the PFE sensors and even the O2 sensors.
All these sensors help the PCM to set the EGR valve. Double check the codes. Next I would take a DMM to some of the sensors. Of course I would listen to what some of these other guys said too.
I'm not sure how similar the fox computer is to the EEC-IV on the 94/95's.
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1995 Mustang GT