Sounds to me like the intake air temp sensor is continuing to tell the computer temps are low after warmup, so she keeps throwing a rich mix. Like a stuck choke on a carb. Thats the thing stuck in the rubber hose going to the air cleaner box. Wiring for it could be damaged or it could be bad. Would be easy to check what it is "saying" with a scan tool. If its staying in closed loop, there ya go. Might run like crazy but its hell on cylinder bores and cat converters.