If you can read data logs, use your sct device to monitor lambase and lambda on bank 1 and 2... They should be very similar to each other. If one of the lambda readings is WAY off of lambase or not reading you can identify if the Wideband is working correctly. Sometimes shop heat them up to get them out of the stock pipes which can damage them. It may not be obvious via visual inspection.
I HIGHLY recommend loading a good known tune to see if the issue follows a different tune. It's quick, easy, and could potentially save you a lot of time troubleshooting sensors.
Based on the description of going into limp mode it's not the sensors down stream of the cats.
Good luck!!!
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