Can anyone tell me what this part is coming out of the throttle body please?

 

Idle air control

 

Also known as IAC valve, they can be cleaned , be careful handling them, they do go bad, but rarely....
I would be more suspicious of a TPS or throttle position sensor if you are having problems with driveability.

The IAC only comes into play when idling, most often a bad IAC will show up when the engine wants to stall when he AC is turned on .