1994 c280.

Dealer replaced the crank sensor. When I drove in it shifted fine. When I drove out it shifted hard. The shifts are so harsh you think it is going to break something.

Research said a vacuum line is probably disconnected.

Diagnosis by said dealer: It is the Oxygen sensor -- no vac lines loose.

Now, maybe I'm missing the boat here -- but:

1. How does an O2 sensor cause this?
2. How did that mysteriously start at the time of that repair?
3. By the way, the duovalve also went out about 3 days after this repair.

Something fishy here. Thoughts?

__________________
1994 C280, dark green metallic
105k miles

1991 190E 2.6, Black
191,500 miles
(sold to another forum member)

2003 Chevy Tahoe LT, Redfire Metallic
105k miles

1989 Mustang GT Cobra Convertible
43k miles