My Dodge Grand Caravan 2001 is pushing out gas through the Muffler. I took it to a mechanic who found with the computer scan that Cylinder No.1 is not firing. The problem was diagnosed to be no signal from the ECM. The problem was resolved and the vehicle was okay for around 500 Km. The problem came back again with the Cylinder 1, but this time replacing the ECM does not solve the issue. The injectors were swapped to identify the problems but not change in the symptoms.

Does any body have any similar experience / or any clues?

Thanks

Wahid