Loss of Power

I was coming off a main road into a neighborhood and I'd say at 30mph, I had a drop in power. RPM's went down to 400-500 while coasting and the engine was making a squeaking noise. Noise seemed to be coming from the serpentine belt area.

Quick visual inspection while shut off didn't show anything obvious. Retried and the vehicle started up. Everything ran fine later that evening and this morning.

My initial thoughts are either fuel related or electrical.

Any input?

Thanks.

Forgot an important fact: No MIL illumination

I'm betting that you have a belt driven pulley going bad, and when it heats up, it starts to seize dragging the motor down. When it cools off for a couple of seconds, it frees back up. Do a thorough inspection of all the belt drive accessories and I bet you'll find your issue.