i have a 95 f159 5.0 with electronic egr valve. can't figure out low egr problem.

 

Might be a bad DPFE sensor causing the issue. These tend to get filled with moisture over time and the electronics in them corrode.

 

Could be a crack in the EGR to exhaust manifold supply tube.. They like to crack in the flex area.. Or, possibly the control solenoid, vacuum lines split/broken or a bad EGR diaphram.. Don't think the 95's had a DPFE, wasn't till 96

 

How about a partially clogged EGR passage. That truck is fairly old.