Have replaced the emissions sensors several times last few years. Unusually, recent hot, heavy Interstate driving and same on local roads also been caught in traffic jams. So once again the emissions light appeared on dash. Any advice or suggestions?

Resetting fixes briefly but then light appears again. Am using high-test on sugstn from friend who says avoid ethanol mix at lower octanes because it screw the oxygen sensor.

BTW No overheating. No other problems despite 177,000 mi on my 2000 XJ. Lousy mileage but that goes with the territory.

Are you sure that it is the O2 sensors that are causing the light to come on? What brand sensors did you change to? The Jeeps seem to run better on NTK O2 sensors than any other brand if those are the sensors you are referring too. Do you have federal emissions or California emissions? Federal is 2 O2 sensors and California is 4 O2 sensors. Let us know what codes you are getting from a scanner after the light is on, we will be able to help out a little better.
And running High Test gas in your jeep will not really change anything it was designed to run on regular. I tried it and got worse mileage running high test then regular.

You might get your codes read free at an auto parts store as you are not in CA or Hawiee. (against state law there). Then post up the numbers, there are guys here that may be of help from there. The light on could be loads of things. An ageing 02 sensor might not even throw a code.

Thanks. Not sure what replacement mfr I used last year but will certainly get the code readout numbers and post here -- just not yet. BTW Fed standards not California. I am in New England and (offroad) Upstate NY Adirondacks.
I say again, I appreciate the help.

Don't know what you mean by "lousy mileage" but bad O2 sensors will do that. +1 on the NGK/NTK brand.

Really. I had just assumed it was State since it's only two. Wonder why the fed would outlaw code reading by auto parts stores in just two states.