Engine light comes on when instrument panel does not work

I have 1996 Dodge Intrepid. The instrument panel gauges sometimes sticks and doesn't work properly. I was told by a Midas mechanic who fixed the problem previous to just hit the dash board and it will unstick. I was driving down the road, hit a bump and the check engine light comes on. I was also told by the same mechanic to hit the dashboard and the check enginel light would go out. That fix works intermittently. The light will sometimes go out but not all the time. The mechanic indicated that I may have a loose connection behind the instrument panel and eventually I may need to replace the instrument panel. Is the problem that extreme? The car actually runs great, I have no problems outside of the check engine light and the gauges sticking. If the instrument panel needs to be replaced, what would that typically cost?