I have a 2002 dodge grand caravan sprot flex fuel and it kicked out a p0171 code. It started to run like hell. Bogged down and sputtering. If I rev the engine it lets out a cloud of black soot./ Not smoke but soot. And there is fuel in it. The soot is wet. I changed the MAP sensor and checked for vacuum leaks. No dice. Im wondering what your next stepo would be.