2001 Dodge Intrepid Repeated Stalls then engine light comes

Occasionally when the car is brought to a stop the engine would shake and the car would either stall out or the engine light would come on. Usually, when the car stalls it would re-start on the first try and the car would run normally with some slight enigine noise. The engine would continue to run ok & generally after 3 starts the engine light would go off. This had been going on for about 3 months. One time the car stalled out and would not re-start but after several failed attempts it did so after allowing the car to sit for a few minutes. The engine light came on as usual. Also, excess smoke has been coming out of the tailpipe, since purchase 2 yrs ago, and continues to do so. I was informed about 6 months ago by a repair shop that the engine needed replacement due to bad cylinders 1 & 6. However, at that time the car did not have the above issues with starting, stalling or the engine light. Is this a sign the engine is failing or does it sound like some other issues? Suggestions?