[Yoitsbeemer]

Hello first time posting I hope someone can help. The car is falling on its face under acceleration. The data logs show I'm losing rail pressure with acceleration. No codes come up. Is there a way to tell if its lpfp or hpfp or just a sensor ect.... The cars does run fine at low rpm and idle. Any help will be appreciated

[RossBMWZseries]

Issues like yours can be a bit tougher to target without any codes. I've read there's "shadow codes" or something like that. Basically your car won't give you a SES (aka CEL aka MIL) but if you run a scanner on it you could get a few codes. If that doesn't do anything, my suggestion would be start with the basics; check all connections, sensors, make sure everything is clean, no deterioration anywhere, perhaps clean the intake and MAF, throttle body, check your coils and spark plugs, you know, do all the things we hate to do.

[Yoitsbeemer]

Thank for reply. I have checked everything all connections plugs coils ect.... Look fine. The 2 codes I'm getting are 2bde 2bfo. I do have mhd stage 2+ tune on the car. Should I tune back to stock?

[Evilchef71]

You should probably shoot over to the MHD thread in the n55 section and post some logs if you have them. They are all pretty helpful and such....