Good day, 2 weeks ago I replaced the pressure switch in my furnace. It is a Lennox Model C33 - 31A - 2F - 2. The furnace ran fine and then stopped cycling. If I unplug one side of the pressure switch, the inducer starts, then plug it back in and the furnace will heat until thermostat kicks off. Then it will not cycle again unless I repeat the above. Please help.

Sounds like the pressure switch is sticking closed. The most common cause of this is moisture getting into the switch.