so you did a code reset?
on the OBD1 there should be 2 checks, a prestart and a run check, my vacuum leak by the throttle body was in the T valve, its a rubber splitter and mine had a hole in it big enough to stick a pencil in, that 1 piece was causing 14 differnt codes, this i recommend to be replaced by a new style plasic T, i also replaced the vacuum hoses to the climate evap canister with slightly larger hoses instead of those brittle plastic thin ones, pulls more vacuum making the vents blow slightly harder, cools and warms inside really fast now
i will also mention, if you have a stock intake, check where the resinator/noise dampner meet the breather tube, that sleeve will break and cause a bad leak, and also where the breather tube sits around the throttle body that the rubber gasket is in place and secure, dirty air filters can also throw engine codes if the MAS (which can also show as an o2 sensor code since its getting a wrong air/fuel ratio ) isnt reading properly, if it cant pull air thru the filter, itll pull it from somewhere else