Dodge 2.0 l Journey Diesel engine revs ok in neutral up to 5000 with a very tiny bit of black smoke when it its around the3000- 4000 rpm range ....a little bit of a stutter sometimes but not all times.... but when I put it into drive or reverse (Automatic) it will have hardly any acceleration it will labor slowly increasing rpm to 2000 then drop to 1500 with lots of black smoke out of exhaust and absolutely little to no power ....also no engine light is ever displayed.
I have taken off the airflow sensor and disconnected the filter box and it didn’t make a difference and I did also try cleaning the sensor which also didn’t make a difference.
Any suggestions as to what the problem could be or next item to check ?