I have an 05 2wd 3500 drw auto,300,000 mile. its doing some strange things and it shows a voltage low to apps code .New apps installed a week ago no change

1 blowing black smoke when stomping on it...Its a stock truck ..no mods

2 when you let up on the acc pedal the rpms drop real slow and in stages sounds sortof like a rice burner (wum....wumwum..wum wumwumwum..wum) sorry for the bad sound affects But the rpms hang and you can see it also in the tach .

3 trans wont up shift unless I let up on the throttle!


is there more then one problem going on hear? and help would be great.