Hi one of techs has an on going problem with the above vehicle. The vehicle will run OK at low speed but once above 50mph it will "Hic" put the MIL on then go into limp. With the pumps egr fuel rail sensors all being common on these we cleared all the faults and replaced suspect parts being egr and fuel rail sensor. We are still left with P0089 code. Road testing on live data we are getting good fuel pressure and when the fault appears the fuel pressure is good and doesn't drop. Fuel filter also changed and checked for filings non found. We found #1 injector to be working but but the variable correction amount was static on the live data. Replaced the injector but still static. The only thing I can think of now is an ECU problem? Any thoughts would be appreciated.