1989 PONTIAC FIREBIRD ROUGH IDLE

Engine Performance problem
1989 Pontiac Firebird V8 Two Wheel Drive Automatic 140000 miles

I had just bought a 1989 firebird formula 350 sounded good till I bought it and drove it home, it was sitting for a few years so I probly shouldnt have drove it home but I babyd it. I bought spark plugs, wire, air filter, pcv vale, fuel filter, oil filter, everything for a good tuneup. But before installing any of it I brought it over my gf's brother in law who is good with cars, it was idleing at about 1k rpm, and when I was driving it it seemd like if I didnt press on the gas a little the engine would hesitate a little. Also you can smell alot of gas when it is running. He tinkered with it a little and got it to idle around 500 but kept jumping a few hundred. Then he checked it with his thing idk what it is. Error cods like 13, 22, 33 came up. He told me to go out and buy a throttle postion sensor and a idle aie controll motor. Was wonderign what you guys think