Cold Weather causes Reduced Engine Power and SES

[Galveston County]

The past two years, when the coldish weather rolls in (which isn't too often in the Houston area), my firebird starts up fine. However, as I shift to 2nd, or 3rd, or sometimes 4th gear, my engine suddenly loses a lot of strength and the Reduced Engine Power light immediately comes on, along with the SES light. When I shut the engine off for as short a period of time as 10 seconds, the SES light will remain, but the enginer power is completely back to normal and the REP light is gone. As the car warms up, the chances of this condition returning decreases. I would be interested to hear some guesses as to what could be causing this...

I know about auto zone and how they check the SES out, I just want to hear some opinions first.

[BLLDOGG]

check it, then we can give opinions