Yes, they degrade in a linear manner and the threshold for CEL or memory code allows it to be pretty bad before a CEL or code is stored.

Put another way, the sensor has varying degrees of good to bad and the computer can only tell you that it's good or bad..not "how good" or "how bad".

Brian


Quote:
Originally posted by tim935:

Could you have a faulty O2 sensor without getting a CEL or memory code? I've been meaning to replace my two sensors for the longest time, but without a fault code....why bother?

Just curious. Thanks!