CM870 turbo issue

[Chamberpains]

If its deleted then yes 1st stop is having the programming checked. Can't go any further diagnosticly till you know the programming is correct.

If it a stock calibration with the EGR still intact and operational, then you need to do a full EGR tune up to be sure everything is working as it should in the system. Then you'll need to monitor if the ECM is derating (using Insite) and fix whatever its showing is causing the intermittent debate. if none of those are going wrong then you'll have to test and check the VG air actuator circuit for leaks. Even the most minute leak will mess with this air circuit. It need to be completely sealed and zero kinks anywhere. Insite has an on/off test that will allow you to check for leaks. If all that looks good then you'll probably be looking at a faulty VGT actuator {air} control module. There is no easy or good or cheap way to test them except swapping it with a known good one. If it needs replaced spend the money and buy ONLY a new OEM Holset control module the rest are junk at best. I know from a lot of past experience.