You mentioned changine the Fuel distributor, intake mainfold, but I did not see if these were adjusted to work correctly.

Steve is right, this might very well be a plugged CAT, but it could also be an array of other things especially after you had all this work done on the car.

Start with the exhaust, go from there.

xp

__________________
1985 190E 2.3L - a constant project.