1994 E-420 check engine light

I now own a 1994-E-420 and the check engine light has come on, I have read the code and it flashes 26 times, what is the problem.?? :naughty: :smokin: But the car seems to run great, and of course here in
colorado it will not pass the emissions with the check engine light on. Can this problem be fixed, and if so how do you go about repairing this ugly problem?? any and all help would be appreciated. Thanks to all, Ben

Pull the entire pod from the dash (friction fit) and reach behind and remove the tiny bulb. Replace the instrument pod. P.