A HEGO sensor is a Heated Exhaust Gas Oxygen (O2) sensor, or an O2 sensor for short.
Your car has four of them.
If you would have bought the sensor yourself, you could have gotten it for ~ $60-70.
Three of the four sensors are relatively easy to replace and would definitely take less than two hours (even for a beginner)!
If you find out the CEL code that was pulled, someone can tell you exactly which sensor it was and about how long it should take to replace.
96 Contour SE
Duratec V6 24-valve 2.5L ATX
108,000 mi.
Replaced: crankshaft w/ DMD, EGR valve (clogged), EVR, DPFE, PCV valve, evap emissions hose & tube (cracked), window regulator (broken), LH & RH PCV tubes, UIM gasket (leak), ignition coil
| 
