I agree with Drift's explanation. The O2 sensors tell the ECU to run rich or lean, depending on O2 "sensed" in the exhaust. I believe it causes leaner when its colder and richer when its hotter (or vice versa, I forget). If there really is something wrong with the sensor, it might be richening when it should be leaning or the other way around. Too much fuel in the mixture (rich) causes sluggish performance. The voltage on the O2 sensor according to the scanner was too high.........the higher the voltage, the richer it runs the mixture, so that goes along with creating sluggish performance.

But since my CEL hasnt come on, I cant really be sure its a bad sensor. And the fact that both O2 sensor heaters were showing the same "fail high" leads me to believe that both would be dead, which is odd for both of them to go at the same time.

As far as the scan tool, its an AutoXray EZScan 4000. My dad got it off Ebay for 259 from Levine Automotive here in CT, and I was able to just run down to the local Levine and pick it up (Ebay BIN price was 40.00 cheaper than the store). So far I like it, but I hear there are better models out there that can also analyze the "sub-computers" in the car (i.e. airbag computer, tranny computer, etc), but they are much more expensive as well.

-Chris