I have been having terrible detonation at low RPM recently and found the culprit. My TC is locking as soon as the trans hits 2nd gear and remaining locked despite my attempts to keep it unlocked by setting the apply MPH tables to 255mph in every gear. I also set the TPS unlock tables to 5% across the board and the converter will not unlock even with 40% TPS. I ran into similar problems in another truck with the converter not responding to any input from the flash. The vehicle is a 2005 GMC 2500 (4l80e) truck. I have logs available and a calibration file if it will be useful.
Thanks in advance,
Henry