Vauxhall vectra B.. multiple issues.

[Furax]

Friend brought in his vectra-B 2001 X1.8XE lump (petrol). Think its the SIR model, he bought it without any advice. 60k "genuine" steering wheel worn to buggery and engine mounts ruined. Add that to the week after it was bought various bits of cardboard fell off the dash cluster revealing may warning lights.

Engine -

P0170 - Lean Exhaust (present)
P1555 - TPS load signal not plausible with engine load (not present)
P0100 - Mass or volume air flow circuit low inputs (not present)

ABS (430 module) -

C0121 - Selenoid relay circuit malfunction (Present)
C0090 - RR Exhaust solenoid valve malfunction (Not present)
C0080 - RL Exhaust solenoid valve malfunction (Not present)
C0070 - FR Exhaust solenoid valve malfunction (Not present)
C0060 - FL Exhaust solenoid valve malfunction (Not present)
C0095 - RR Inlet solenoid valve malfunction (Not present)
C0085 - RL Inlet solenoid valve malfunction (Not present)
C0075 - FR Inlet solenoid valve malfunction (Not present)
C0065 - FL Inlet solenoid valve malfunction (Not present)
C0800 - Switched battery voltage low (valve relay) (Not present)
C0232 - Brake system control light voltage high or circuit open (Not present)

Cleared all the fault codes, the C0121 came back and the ecu light stayed off on idle. I couldn't test drive the car yet but will be doing on sat to apparently the ecu light comes on after a few miles of driving. Has anybody got any guesses of where i should start first since the faults seem to indicate lambda, maf and tps?

Car seems to show signs of running rich and the idle is very poor, hunting and stumbling but not cutting out.

Im guessing the ABS ecu is toast or the abs pump itself? Can this be swapped with another without coding or do i need opcom?

Thanks