I have a 2008 FatBob and have recently had a bit of an issue with it. It started running pretty rough and felt like it had a miss when I throttled it. That cleared up for the most part but a few days later it was really hard to start and wouldnt stay running. That has gotten better but seems like the rear cylinder is running hotter than it should be. I checked the diagnostic codes and only ONE came up... P0151... O2 SENSOR LOW. I assume this means a lean running condition from the apparent temperature of the cylinder. What could be causing only the rear to read like that? Bad O2 sensor? Maybe the O2 sensor is fine and the injector is clogged and restricting fuel? Any ideas guys?

 

I'm sure everyone who tried to help me out will be interested to hear that the issue was in the ECM and going in for the the stage 1 upgrade and reprogramming the fuel delivery system solved the issue. Thanks for all your help. Hope this helps someone else in the future.