[WillLowe]

my car has now been in an out of the garage for 7 weeks (435d) the car was remapped then 2 days later there was no power as if the large turbo wasn't working. I took the car nack to the garage who are a well known company in the UK that I and many others have used before, anyway they removed the map back to standard at which time a transmission warning popped up and kept the car in limp mode. From there they replaced the fuel sensor, maf sensor, turbo actuators yet no luck. They then send it off to an automotive electrical company who replaced the boost converter, tested the ECU on a proper rig and the faults cleared.

However on the way home the car has went back into limp mode, this time with new fault codes. Does anyone have any advice on where to go from here judging by the codes below

245A00 hot air mass meter, air flow too low
292100 charging pressure controller for high stage turbo electrical, mechanical or excessive temperature
27B900 exhaust back pressure sensor before turbine exhaust gas pressure too low
244C00 charging pressure control, pressure too low

[Enabled]

Have you physically inspected the turbo or the pipes?

Smoke test for leaks, visually inspect turbo for damage.

[WillLowe]

I havnt personally but the garage say they have looked but nothing shows. Im unsure if they did a smoke test or not

[Soul_Glo]

Who remapped it? If this started after a remap. It could be a bad map. Flash to stock. Issues gone? It's the map. Issues remain? Then read on...

Sound like a dpf pressure sensor to me. What's your driving? Short runs? Is she regenerating? Try force a regeneration and if it fails it's possible you have an emissions issue. You can also check the dpf soot/ash content with carly bmw or something. What's your mileage? Dpf could be clogged.