Code Help: 31 & 67

Hey guys, been a while since I posted.

89 LX, CEL came on not too long ago.
302 5.0L
5 spd

Codes 31 & 67


I have read numerous trouble code listings, and 31 seems to be EGR related.
How do I go about diagnosing what is causing 31 from your guys experiences?

67 seems to be a clutch position sensor, which I am not familiar with.

Thanks a ton for the info on the EGR.

Any idea on the clutch code that is being thrown??
It's one I have never had before, and not one in the normal barrage of mustang issues that I am familiar with.