I thought I would add this information to the forum as it might help someone.
A couple of weeks ago I had the dreaded "Reduced Engine Performance" message come up and the car limped home. It wouldn't go above about 2500 revs in any gear. I called out LR Assist and the guy read the fault code which explicitly stated that Exhaust Sensor 1 was failing and that it was only reading 20C instead of around 380C. We looked at the telemetry and it all looked conclusive. Car goes into LR dealer who change the sensor, I drive home and as soon as I go up a hill the message comes back so I turn round and go back. Given that it happened when going up a hill I was beginning to think fuel starvation.
I got the car back yesterday and now it seems OK and they had changed Sensor No 2 as well. The service manager said that you sometimes get this where the a failure in one sensor causes the engine management system to compensate somewhere else and throws up the wrong code. In this case the code was P0546-00. 3 x FL1 2 manual + 1 auto
5 x FL2 4 manual + 1 auto
Now Discovery Sport P250 MHEV SE