2002 dodge durango idling hard and stalling

At that age it's a money pit , Get something else , Oh that's right No one can afford anything these days , Oh well

I just bought it and it has 124,000 miles I’ve only owned it 3 weeks it’s what I rely on now especially since winter is coming

I’d also like to point out,it went to the mechanic on Friday because of this issue and the vacuum hose was replaced by him he thought he fixed it but come yesterday morning to today it’s still idling hard and trying to stall. Codes read as followed PO128, PO456, and PO121

You need another mechanic , Personally I don't know what those codes are , Hopefully you didn't get taken , Look for good motor to chassis ground ( ? )

The codes all read from the engine light and my uncle is a mechanic he explained that they are, my durango is at the shop until tomorrow unless he finds more wrong with it. today it idled normal but while accelerating it almost felt like it didnt know how to switch gears said i was going 55 but felt as if i was only going 25 and when i slowed down it would do a jerking movement. hoping the problem is fixed soon as to i just bought it and cant return it. Also my uncle isnt the one working on it otherwise it'd be completly fixed already and i wouldnt be asking for help. thank you all whom are giving advice. this mechanic has fixed multiple vehicles of mine and this is the only one hes had problems with every other one hes fixed right then and there.