I need help, Commanded AFR not normal

[axekick]

I mentioned this in my other thread but this is for a specific problem. I was looking over my log and I noticed the commanded AFR at 13.6. It changes to 14.8 for a little while and then back to 13.6 or 13.7. Its in fuel trim cell 20 most of the time but it goes into normal fuel trim cells occationally. There doesn't seem to be a correlation between FTC and AFR. I'm going to go for a drive at lunch and log it. I wasn't logging O2 voltage before but I will this time. Any initial ideas of what could be causing this? I'll post my log and tune after lunch. Please let me know if there's anything else I should log.

[Higgs Boson]

there are a lot of adders and multipliers that can alter it if they are enabled. post your tune when you can.

[axekick]

Alright, here it is. One log with the stock flex fuel AFR table and one with the table set to 14.57 across the board. That is the tune I posted. Otherwise the tune was the same in both logs.

I'm pretty sure its doing some kind of Catalyst test. I really wish we could disable that like the Gen 4 trucks.

You can see in the 14.57 AFR table log that it died once at a stop light, but I don't think thats related to this problem. Its my own idle tunings fault.

[axekick]

I can tell that its commanding 13.88 due to the fuel comp sensor because right before I go WOT its commanding 13.88 and when I go WOT it commands 12.08. 13.88/12.08 = 1.149 which is exactly what I command for PE. So my fuel composition sensor as well as some kind of catalyst test are apparently contributing.

[axekick]

I thought I'd bring my old thread back because I've run into this again and have still not found the solution. I was tuning another 06 and had the exact same issue. Driving in closed loop, commanded stoich goes to .92, stays there for a while and then goes to 1.08 and stays there for a while. I tried stock DTC settings, COT off and on as well as other stuff. I can not figure out why it does this. I always thought it might be the catalyst test but Bill tells me there is nothing like that in any gen III truck. So now I think it must have to do with the flex fuel system. I'd like to see a master disable/Enable switch for this like the gen IVs have.