We replaced a faulty high pressure fuel pump on this car a few months ago and the customer has just returned it to us with an intermittent fault causing engine light to come on.

Codes recorded are -

2A2B Mixture control, mixture too rich.
2AEC Nitrogen oxide sensor, self diag. Limit value two exceeded.
29E0 Mixture control - mixture too lean.

I ran through an adaption clearing routine and road tested the car but it runs slightly rough at light to medium throttle and apparently won't go into closed loop. Both B1 and B2 pre-cat O2 sensors stay at 2 volts.

This is the second time I've seen this and would love to know a bit more about it!