Right car still isnt running 100% occasionaly get a few flat spots and occasionaly cuts out when stopping at traffic lights will happen maybe once every 6 weeks or so. The flat spots are down to this code
17705 - Pressure Drop between Turbo and Throttle Valve (check D.V.!)
P1297 - 35-00 - just havent found the split hose yet

but was wondering if this code
7545 - Fuel Trim: Bank 1 (Add): System too Rich
P1137 - 35-00 - -
could be the pre cat lambda, as already had new VW Maf and quite rare for the Fuel Pressure Regulator to fail it seems
17545/P1137/004407 - Fuel Trim: Bank 1 (Add): System too Rich
Possible Symptoms
Malfunction Indicator Light (MIL) active
Possible Causes
Mass Air Flow (MAF) Sensor faulty replaced
Fuel Pressure Regulator faulty
Fuel Injector(s) faulty unlikely
Oxygen Sensor Control faulty
Oxygen Sensor(s) faulty
Evaporative Emission (EVAP) System faulty
and what is the oxygen sensor control thought that was done by the ecu

so was wondering when other people have had the pre cat lamda fail what symptoms they experienced