where are the upper and downstream sensors located? is it hard to change them? and where is the speed control sensor located? is it hard to change?
Upper and downstream oxygen sensors?
upper is the oxygen sensor before the catalytic converter and downstream is after the cat.
I think you are talking about the vehicle speed sensor and that is located near the output shaft of your transmission.
the VSS is normally pretty easy to change and the oxygen sensors are normally a bit tricky because sometime you need a special socket because they rust themselves in place a majority of the tiem
Upper and downstream oxygen sensors?
well type of car/truck would really help.
