Gtsboy said:
Do these things fade out over time and power loss, or is it a work fine, then crap out deal?
My exhaust is off the car right now, replacing in the coming week or so. All sensors are broke free right now. Car has 25,000 on it as of now. Should I toss them (all 4 or just front 2??), or wait until it throws a code, guess it wouldn't take more than 20 minutes to change them even after the car is back together.
Like I said, on a typical car, they'll last ~50k miles. However, we all know how much heat Vipers generate, which certainly isn't fantastic for an electrical device. (O2 sensors do have to reach a certain operating temperature to function, though, so you do want them to stay pretty hot.)
O2 sensors heat up and cool down during their normal cycling. As such, their voltage outputs raise and lower cyclically. A properly-functioning O2 sensor will "toggle" back and forth pretty evenly. When an O2 gets worn, it will be very lazy to toggle or won't even toggle at all. That's what happened to Mr. Shoe's O2s.
Think of it this way: the O2 sensors monitor the oxygen content of the exhaust, which is the end product of the entire combustion cycle and every other sensors' input into how the car should run. If the O2 sensors aren't sending the proper signal (voltage) to the ECU, the car won't run right.
In layman's terms--keep those O2 sensors fresh! /images/graemlins/smile.gif