Anyone ever heard of this?
After jumping through 50 hoops today, this was the code my truck had thrown yesterday. I think it needs an O2 sensor in Bank 1. but others have said that it may also be a vacuum leak.

I HIGHLY doubt it is an Intake leak, considering i just did all that crap.

 

HEGO, means the 02 has not switched fast enough for the computer. It is different from the lean code 171.

Check the fuse and the wiring. If those are good then swap the sensor to the other bank to see if the problem stays or moves.