need help setting timing

I replaced intake manifold gaskets because it leaked antifreeze. Put it all back together and forgot to plug in to distributor. Started it up, truck ran horrible. Found that I forgot to plug into distributor and plugged it in. Restarted, and still ran bad. I have a car medic diagnostic, plugged it in and got 7 codes. Unplugged it, plugged it in again and I got 10 codes. Is there any way to test the computer to see if there is something wrong with that? Or what should I do?
Thanks
Scott M