The purpose of 2 oxygen sensors is to test the efficacy of the catalytic converter.
While the sensor itself can be out of whack, or excessive resistance within the connector doe to contact oxidation could also send a Mystifying voltage back to the engine computer, it is also possible the catalytic converter is no longer able to perform its function and requires replacing.
Try banging on it with a fist and see if it sounds like things rattling in there.
If so, it is likely that honeycomb grid has collapsed and is presenting more resistance to exhaust gasses, which will limit power.
The code you received means investigate the exhaust components and the wiring/connectors to the O2 sensors. it could simply mean replace the after sensor, or both pre and post sensor and the CATCon.
And the Caig Deoxit is magic electrical juice, but I am shying away from the Spray cans and recommned D5 in a bottle. very little is required.
https://www.amazon.com/Booster-Elec...qid=1490554603&sr=8-8&keywords=caig+deoxit+d5
d100 is the full strength version for severly oxidized and dirty contacts, and should not be left on after it dissolves the oxidation.
D5 is the version one can apply and reconnect.
No other electrical contact cleaner actually does anything about the oxidation on the conductive surfaces. They are good for flushing out old crusty contaminated dielectric grease though
Any connector i open up gets Deoxit on it, and the precision swabs usually turn black and get shredded, even when the contacts look shiny and smooth. After Deoxit they are like oiled gold/chrome.
https://www.amazon.com/Tamiya-Craft...&sr=8-3-fkmr0&keywords=tamiya+precision+swabs
https://www.amazon.com/DenTek-Profe...ie=UTF8&qid=1490555039&sr=8-7&keywords=dentek
The sprays, i think they having issues with the amount of Magic they stuff in the can. There should be a slight pinkish hue on a Q tip or white paper towel, and my latest 2 cans are devoid of this, and do not seem to clean as well.
I'd First deOxit the 02 sensor connectors, remove battery cable to reset engine computer then drive again and see if code returns.