Whining noise

[2003XLT]

Hello,

I have a 2003 Ford Expedition XLT 5.4L. I have been hearing a whining noise coming from the front of the engine. I popped open the hood and it is def. coming from the front of the motor. When I hit the gas the whining noise gets louder.
Plus I noticed that the check engine light is on. Went to AutoZone and had them test it. It pulled up a P2196 code. System running rich.

Any suggestions as to the whining noise and the code? Where do I start start?

Thanks in advance for your inputs!

 

[Jackmldog]

Whining noise is probably the alternator bearing going bad.. But as for running lean it could be many things