Hi
I have a94 lesabre and had the same problem since last dec. never got a code for the EGR until about a week ago after the check engine light started coming on everyday, the scantool said EGR pintel circuit !??. I took a chance and bought one at the wrecking yard for $45.00, put it on and it hasn't missed or stumbled or stalled since.
I am delighted, Hope this finds you before you get too much more money into this.
Rick