Speedometer/Speed sensor problem Help!

Car: 95 Civic VX.
Problem:
Check engine light on. Code 17 Vehicle speed sensor.
Idles up and down.
Speedometer stuck around 20mph while driving at freeway speeds.
Replaced speed sensor from the dealership.
Check engine light still on with code 17.
Any ideas? Is this a common problem?
Problem:
Check engine light on. Code 17 Vehicle speed sensor.
Idles up and down.
Speedometer stuck around 20mph while driving at freeway speeds.
Replaced speed sensor from the dealership.
Check engine light still on with code 17.
Any ideas? Is this a common problem?