Noob here, first post. I have a 2016 E550 Coupe (C207, M278 4.6L twin turbo) and have questions.
I hear the ECU on this can brick when I try to use an HP Tune, or apparently it's some "PCM modification" you need to do before you use HP Tune. This of course worries me a great deal because I've been looking for a replacement ECU and it's just short of impossible. So rather than replace it, I figured maybe I can adjust mine via the tune and get it working right. But I can't afford to brick it...
My problem is low boost, about 7-8psi when it should be 13, and it's being commanded to do this, it's not a mechanical issue. The MB Dealer says nothing is wrong because Xentry says so. So annoying... I have Xentry too, which is basically useless imo.
I also have an OE Tune which bumps the boost to about 12psi, but I'm guessing it should be more like 17? My options are likely zero in finding the actual problem so I thought I could simply force the boost higher with HP? If it's shorting me 5psi, or x%, then I bump boost in the tune to that much over what I actually want and I'd imagine it would work? Eg; plug in 23psi and net 17.
I also heard tunes like OE don't play well with HP? I don't know what that means, but if so, could I use HP to see what all the OE settings are, then remove the OE tune and duplicate it in HP?
Thanks