Thanks for the reply. Much appreciated!
Once the furnace goes into the "limit switch stuck open" code, it never works correctly again. It keeps blowing cold air forever. It doesn't attempt to light at all once its in that mode. When I switch the power off, wait a while, and then turn it back on, the inducer spins for a quick second, it sounds like it wants to start its normal cycle, but then after a series of clicks from the relays on the control board, it goes into that same "cold air" mode. This all happens even though I have the thermostat cranked!
At this point, I'm thinking of changing out the Control board and see if that does it.
But just so you know...Once in a while, (especially if I shut everything down overnight),it will actually do the correct thing after I turn the power switch on The ignitor works perfectly and the gas and blower motor all seem to work correctly. But eventually...it funks out again.