940T, 265k. Starts quickly, runs strong, has recently developed a lumpy idle only after warmup, and the tailpipe shows a lot of carbon. Mileage is not what I want. 18.5-19.5 in mixed driving, which is what the fed mileage site says, but is far lower than many claim. Anyway, I have no record of the 02 sensor ever being changed,
The question is related to, how to read O2 numbers with DVM. A friend and I read the sweep of the numbers, which run from abt .1 to a high of .82, over several readings per second. That is, the scale gives several numbers in a range over a short time, but they are not the same number range. Now what I want to know is, are we seeing the actual low and high, or is the low and high as though on an oscilloscope, and we are seeing points on that curve so the actual high may not be appearing on the DVM readout unless it coincides just at the right time.
Corollary, will a (in this case small cheap but working) analog VM needle read differently/better?