Oooh, I'll take the first part... Heated Exhaust Gas Oxygen sensor, a.k.a. O2 sensor. "Heated" because the sensor has a built-in heater element to maintain the platinum-coated zirconium sensor at the temperature required to function properly.

(EDIT: Here\'s a nice write-up on oxygen sensors , in case you're interested.)

//> //> //> //> //>
Garrick
Silver E0, #3895 of 6535, built 10/2/97
She's stock. Why mess with a good thing? laugh