The vehicle idles rough. Also had a few codes

Do you have any trouble codes?

check for vacuum leaks!

A throttle position sensor would never cause a rough idle. When they go bad, they usually cause a stumble or hesitation. The air/fuel sensor just monitors how well the computer did. You're looking in the wrong place. This could be caused by many things, from worn spark plugs to an air leak or carbon buildup. Turning on AC at idle puts and extra load on the engine, so anything that would cause problems under load would be suspect.

When your A/C is on it puts an additional load on the engine. The throttle positioning solenoid pushes on the throttle linkage and increases the idle when A/C is on. Some are electric some vacuum You need to check and make sure its not stuck, plunger should get a shot of WD40 and move with finger to work in.
Make sure the connection is good Vac or Elect WD linkage also

Hope this helps Mike

Sounds like the TPS(Throttle Positioning Sensor) or the IAC(Idle Air Control) is malfunctioning. Sometimes these sensors malfunction because of a dirty throttle body. You should clean the throttle body out with throttle body cleaner first. After cleaning the throttle body out, start the vehicle. It will be slow starting and when it does start it will run rough but after a minute or two it will settle down. You will need to clear the trouble codes. Most major auto parts stores will do this for little or no charge. After clearing the trouble codes drive the vehicle. If the vehicle runs properly, no more is needed. If the vehicle still runs the same as before then continue to drive vehicle until the engine light comes back on. Read the codes and replace the defective sensor.

try the crank speed/position sensor as this controls the engine revs as well as other things

The hum is likley your fuel pump priming the fuel delivery system. I would start looking at the wiring coming from the Throttle Position Sensor. With the key in the ON position, you should be getting a 12vDC (or a little higher) signal to one wire and an excellent ground on another (usually the center if there are 3). If you are missing a good ground or the 12v signal, there lies your problem. Good luck.

Have you run a fault code test with a code reader?

get a trouble code from Autozone or other store for free. It sounds like a sensor problem to me. The Idle Position sensor for example.

The idle air control valve (IAC) may be stuck or failing. This solenoid-type device controls the airflow into the engine at idle. It is fed control input signals from the engine's computer. Over time, the IAC valve may become dirty from EGR gases and carbon, etc. It may have a worn pintle (valve head) or the return spring may be weak or broken, causing a rough idle or even stalling from an over-rich fuel/air mixture. The second thing to have checked is the throttle position sensor.TPS. These devices will "flag" a fault on your vehicle's onboard OBD-II computer, which a decent code reader/scanner can display and clear. Third, a dirty throttle body housing/venturi can cause rough idling and poor response. A special cleaner is needed to remove oil and carbon residues from the specially-coated inner surfaces of the throttle body. Fourth; you may have a Mass Airflow Sensor (MAF) that might be failing/malfunctioning. Some vehicles use these instead of the Manifold Absolute Pressure (MAP) Sensor, which you may have. These sensors need to be checked and verified that they are functioning properly. Fifth; check/change your vehicle's fuel filter, and verify proper/adequate fuel pump pressure and flow performance. Don't run your vehicle below 1/4 tank of fuel...doing this sharply reduces the life and cooling of the in-tank electric fuel pump. These are not cheap, or easy to replace!

it could be an o2 sensor. it could also just need a tune up