I do have some other "issues" with my Dak that I think I can resolve (thanks for all the posts and good info) but my question is this, '94 5.2 108k my truck is missing and back firing when cold, well really bad when cold and not as much once warmed, I think it's my thermostat and will fix that monday. Heres my question, when I do a engine code check, (the turn the key off and on thing) I get a code 12 which to the best I can figure out is "battery or computer has recently been disconected" which is true, I disconected the comp to see the s/n off the inside of it (the paper sticker with the # was worn off) and did I mess something up by just re connecting my computer with the battery still hooked up? should I have dis connected the battery, and is there a memory reset of any kind? thanks for the help. Tony

 

I think it's a generally good idea that anytime you do something electroni or electrical, that it's a good idea to disconnect the battery first. It is possible that because you didn't disconnect the battery, something may have happened to the comp. Try disconnecting the battery, wait for a couple of minutes, and then reonnnecting it. See what happens. The problem may solve it's self.