Getting stumped with a 2015 Honda Grace Hybrid 1.5 engine (Non GDI) with an intermittent P0172 DTC with random cylinder misfire counters. This customer has been to a few shops and you name it and it was put on this car to rectify this problem. The vehicle can be driven in sports mode which you are allowed to run the engine continuously. The trims can be reset using a bidirectional scan tool but the trims will return to being negative and my total trims would be -35 to -40%. The vehicle pulls off sluggish and will jerk like a misfire. No black emission coming out of the tail pipe, no gas mixing with the oil, purge valve and pcv were isolated. The trims get better when air is introduced via a vacuum leak or at WOT but once you stop and about to pull off. There is a flat spot. The crazy thing is my AF FB CMD is almost close to Lambda. If this vehicle is pegged rich, my Lambda should also reflect this to agree with the TFT. Injectors were serviced three times, spark plugs and coils were replaced twice, MAF and Map were swapped with a known good. New and used O2 sensors. New air and oil filter, all valves were adjusted, you name it. It was done.The ECU was repaired last year due to a Serial Com failure (P0600). Im thinking I maybe dealing with a faulty processor on this module again.The clues are, pegged riched with no carbon fouling on the spark plugs, no excessive black emission from the tail pipe, no emission smell of unburned gasoline, no idle hunting or rough idle. Flat spot and jerking when acceleration, gets better at WOT. Gets better with vacuum leaks are created, Fuel trims are negative but AF CMD is close to 1. Maf is reading good. The only thing left is a corrupt module or faulty injectors. I hope someone can shed some light on what im thinking. Thanks in advance. #djmobileautoservices #diagnosticdaniel #ATS #HondaGrace