1955 1954 codes limp home

[scooter3kw]

i have a 313cdi 2007 b906 sprinter camper its twin turbo.
this started a year ago i had the limp home come on and diagnostics said it was the glowplug module so i replaced that since then i have been chassing the faults ive replaced to date is the glowplug module,the egr valve, the dpf and pipes,the maff sensor,all map sensors,the inlet temp sensors, throttle body,both turbos fitted 150hp turbos,new plastic inlet manifold and gaskets ,new inter cooler fitted,new ambient temp sensor fitted behind bumper,new ecu,found a short in the glow plug wiring and solenoid valve repaired that and isolated the short and new fuse fitted ,replaced the solenoid valves,fitted new lambda sensor,fitted a decat pipe and no difference so put cat back on,fitted new exhaust temp sensor and still i have the engine management light flashing and the limp home on the only current codes are 1955 and 1954 they have been there the whole time.
any body know what this is??

it says glow plug module but ive already replaced it the van runs sweet and if the turbos would boost it would be fine .
im no amateur at this but i retired from the trade in 2008 so these systems are fairly new to me.

 

[Larkone]

Not all code readers will reset all codes - have you tried getting it put on STAR and cleared that way or read the live data?

 

[scooter3kw]

no not yet thats the last resort.to be fair the code reader ive got does all 110,000 carmakers in the world
Ive read live data and cleared codes for the special functions. i use a mucar vo6 with all the upto date software it has no reading of temp exhaust sensor fixed that today but no difference it still reads no temp as in - 40 degrees on kat.i ran afeed directly from ecu and that tells me its the loom it has a wiring fault
the only current obd2 codes are 1955 and 1954 but when checked the special function on the mucar it says 1437-002 b19/7 temp sensor up stream of kat voltage low and throttle valve sticking or jammed but thats in correct as it has anew valve fitted and still shows same fault.so the engine loom needs a rewired.
anybody got a new engine loom for om 646 150 1777 or similar?

 

[scooter3kw]

Not all code readers will reset all codes - have you tried getting it put on STAR and cleared that way or read the live data?

 

[scooter3kw]

An update I've still got the engine light flashing and it runs sweet as. But it's like it's still on limp home just been to a auto electrical engineer and they can't find it either. So I went and I ordered a brand new sprinter should be here soon problem solved.