08 ISX Boost issue

[mhaynes]

A friend of mine has a 08 Peterbilt dumptruck with a ISX that has had a egr, dpf delete done for the past two years. A while back he started having a high idle issue. It would idle at 900 instead of 650. He was told that the ecm may be going bad. He had a reputable tuner in Europe hook up to it and he saw that the file that had been put in it when the delete was done shouldn't of been with that CPL number. This tuner in Europe only puts a tune in that is good for that CPL number. The file that was in it had a lot of added HP. This tuner in Europe reflashed it with one of his tunes and that cured the high idling issue but now has no power in the top gears until it hits 1500 rpm's. It seems fine at a idle and in the lower gears, but when you get in the high side it has nothing under 1500rpm's. When it finally hits 1500 the boost spikes and it pulls great. He pressure tested the whole system and found no leaks. Inspected the turbo and it seems good. While inspecting the Actuator it had a very bad grinding noise in it so he replaced it with a new one. The problem got a little bit better but its still not right. Does anyone think the ecm could be bad from the prior tune? I have never experienced anything like this.