Not really a hot rod question

My boss has a 89 Ford Crown Victoria and it has a load of miles on it. He wants to sell it the only problem is he wants to fix it before he gets rid of it for a couple hundred dollars. I checked it today with my scan tool and it reads these codes: 12, 13, 16, 20, 21, and 74 I can't find any information about OBD 1 on the web so I figured you guys might have some ideas. The car starts up kinda hard but when it starts up it runs ok. I would really like to help him out because he's done me some favors in the past.