O2 Sensors on Vortecs
 

Does anyone replace their O2 sensors as part of their tune-up? If so, when and how much of an improvement did you see in mileage? I am installing an Edelbrock TES and have a chance to change the sensors easily right now but am shocked by the price. Michael

Oxygen sensors do need to be changes every-so often and tune-up would be a good time. I would say a 1-2 mpg gain if the old sensor was really out of whack. Just lazy sensors won't net you much of a gain.