Ive been battling this issue for years.
ive always blamed myself but now im thinking it is possibly o2 sensors? also assumed it was a corrupt file, so i rebuilt the file and reloaded it. Ive also reflashed the controller with factory cal from a MDI module and still same issues occuring.
This 1500rpm and 2400rpm is very consistent at light throttle.
Ive tuned the car in VVE and MAF in OL and all is as great as it can get and no issues what so ever in OL. But once i enable CL, the stumbles come back in those areas at 75kpa or less.
Car is an awesome driver in any other condition.
Below i have some snap shots of the situation occuring and hoping someone else had some insight on this. Tune and log attached as well.CL stumble zr1.hplbandvzr1 factory HC BEST BLEND MAFVE.hpt
It feels like a major misfire and feels like it. it drops out on power at those moments. but again when i command it in OL with the controller, it drives perfect through those areas. Put it back again and it stumbles every time. ive tried to make PE come in earlier to eradicate it and it has helped some so far, but it is getting close to running PE while cruising on Highway.
Ive messed with all o2 tuning settings in every which way and it has not helped the situation at all.
1500rpm stumble and around 2400rpm.PNG
1500rpm stumble CL.PNG
2400rpm stumble CL.PNG