[Sevillian273]

These engines are speed density. They dont have MAFs. They have a MAP sensor but it should set a code. I think they can be tested at auto parts stores.

The engine will run and drive fine with zero EGR flow. I have proven this with my own vehicle by using a block-off plate for a few thousand miles. Theoretically there is some risk of detonation but I have experienced none even with 4 deg advanced timing and 95+ degree Florida driving. Most EGR related driveability problems are caused by the valve sticking in the open position, allowing too much exhaust into the combustion chamber.

DK says it started sputtering and getting progressively worse so that rules out a firing order issue, otherwise it would have run bad from the get-go.

A healthy ECM will advance the timing as rpm goes up. If it has a problem and is not applying the spark curve, the motor will run at base timing(10deg) throughout the rpm band, which would explain a loss of power under load. Thats just one way it may have failed. Maybe it's applying ridiculous amounts of fuel... its hard to say, but with all the new parts and no codes, My money is on a bad computer.