98 1500 4wd pick-up, 318 engine. I am getting an intermittent Bank 2 Sensor 2 high voltage code. Got this info from a scan. Replaced the rear sensor on the convertor (could not find any sensors on the manifolds), had the code removed with a scanner. Code came back. It will clear itself and then check engine light will come back on. Can one weak cylinder cause this? Changed the plugs and one was nasty. Any ideas?

 

You possibly should have replaced the front oxygen sensor, the one before the cat. If your fuel mileage has dropped off lately though, I would guess the front sensor is bad. The heavy duty engines use two oxygen sensors before the cat, which is why the code described the Bank 2, but your truck should only have one sensor in front of the cat. Try changing that one and see if the code disappears.