97 Chev gas Torque Converter trouble, I think

[Flatlander6.2]

Having some issues with my 97 Chev, and want to confirm I am on right track before I start tearing apart. Recently did tune up, was running like a watch. Within 2 weeks, fuel economy dropped by 1/4, runs fine at highway speed, but a little rough at idle, very rough at idle when in gear. It is very cold and icy up here, and when starting from stop, truck wants to spin rear tires more than before, even under very little throttle application. Then when stopping on ice, ABS wants to kick in right away, like rear tires are still pushing. I'm thinking TC not completely unlocking?? But unlocking enough that it won't stall when stopped. Am I close?

[crashz]

Before doing that, check to see if you damaged or disconnected any vacuum hoses. I'm wondering if the computer is trying to over or under fuel due to a false air/fuel ratio.

I've seen converters fail to lock up and only one (Dodge) fail to unlock. The locked converter wouldn't alow you to shift into gear without stalling.