Having similar issue with 02 grand caravan 3.3l.. every once in awhile it would act like it was out of gas and spit and sputter when it did in fact have gas (fuel gauge also doesn't work so i go by mileage) then it just progressively got worse doing it more and more until it did it every time i drove it. Now it misses and backfires going down the road and will also miss during idle, but is definitely worse in drive or reverse and when going up a hill, acts like it isn't going to make it. you can feel a clicking in the gas pedal when it backfires and the oil light will come on when you come to a stop then go right back off.. I have changed the spark plugs and wires, the coil and did tune up. It also decides not to start randomly mostly when it is cold out and has to be jumped. Thinking I will most likely need a new battery as well.. i don't think it has a egr valve? unless i am somehow missing it but it is not above the alternator.. anyone have any suggestions??