Hey everyone. I've been puzzled with strange, slowly switching STFT for a few months and finally found where the behavior started suddenly after a re-flash about 5 months ago. Sorry if this has already been discussed on the forum but I could not find any related threads.
I've attached the tune/log immediately before the problem, where the STFTs look normal:
2020-01-07 Run 74 - NORMAL STFT.hpl
2020-01-07 Run 74.hpt
...and the first useful log and tune after the problem appeared:
2020-01-09 Run 76 PROBLEM STFT.hpl
2020-01-07 -2 exhaust cam Run 76.hpt
You can see the STFTs act much slower.
Here are some potential causes for the weird STFT trends that I think I've ruled out:
- cam phasing changes - NO, earlier tunes used more correct cam phasing and had normal STFT behavior
- bad/fouled O2 sensors - sensors were changed since the problem started, but they did not resolve it
- Adaptives need a hard reset - Battery was disconnected overnight; problem remains
- logging Settings, polling interval, number of channels... - Run 76 was logged with very few channels just to see if the logged fuel trims would return to normal switching; they did not.
I'm probably going to discuss further with HPT Help Desk and/or Hotwire Auto to see if they can help. Just putting this out here in case you all know of other issues.
Background - This is a 2016 6.4 Hemi in a 2008 Jeep Wrangler, NGC4 PCM, harness and initial PCM setup by Hotwire Auto, manual transmission. Stock Hellcat exhaust manifolds. Here's the most current tune and log with newer O2 sensors. The WB fluctuates normally, but the STFTs are still moving more slowly:
2020-07-01 ANN Run 399.hpl
2020-07-01 ANN Tune Run 399.hpt