I've been banging my head on the wall on this for some time. Nothing I do seems to make a bit of difference. This is a Trailblazer SS with a 408 w/ 44# injectors with an E40 PCM and slot MAF. Has ported heads/ cam / long tubes etc. What happens is at a certain load or fuel demand it starts to cut and will go from 13:1 AFR to 20:1 AFR and act like it's doing fuel or spark cut. I've also hit a wall with the VE table as I can only make it go so high and I need it to go higher. I've patched it with the 2bar SD OS which helped some but didn't fix the problem. I have the MAF failed with no SES but it's an auto vehicle and needs the temp sensor data. I then tried to scale the tune with the double Stioch and half IRF & IVT Terms method which did absolutly nothing for this issue. I'm completely lost here. It runs great up to this cutting out issue. I'm attaching the tune and a log file where you can see it go super lean. I have the WB plugged into the AC Pressure sensor. Everytime it happens you can see the KR start to kick in from the lean spikes. Thank you in advance for any help. Maybe I've made a mistake somewhere in the tune, but it's seems pretty straight forward to me.