Random spike in commanded AFR?

[Keudn]

I was driving around logging today and I got a random huge enleanment in my commanded AFR that seemed to happen only in a certain throttle range. It only happened for under a minute, and for the remainder of the drive it never returned. I'll post a screenshot of the section of the log where it happened, along with the full log. Anyone have any idea what is going on here? My first guess is a table that is still set up for 91 octane that I forgot to modify for E85 stoich ratios, but I feel like I have gotten all the tables that I can see with HPTuners at least.


I also had a random huge enrichment issue a few days ago where it would enrich at low TPS down to as low as 0.6 lambda, but unfortunately I don't have a log of that. In that case, it would always be enriched and it took resetting the fuel trims to resolve that one. Don't know if these two incidents are related or not.

leaning.PNG

KC Drive 2 leaned at beginning.hpl
KC Drive 1.hpt

[5FDP]

It's a cat test. If the cat is gone and the rear o2 sensor is also gone, this is why. You can see it go to 16 afr and then down to 13 afr as it's doing the test.

[Keudn]

It's a cat test. If the cat is gone and the rear o2 sensor is also gone, this is why. You can see it go to 16 afr and then down to 13 afr as it's doing the test.

Is this the same cat test that I am getting during OL? If so why does it only go up to about 1.15 lambda in OL? https://forum.hptuners.com/showthrea...-and-small-TPS

(I am aware of my rear O2 code being thrown, working on getting a replacement soon)