On Tuesday, 31 December 2019 08:56:57 UTC, Jim GM4DHJ ... wrote:
Five years ago I got a PO130 code when the car was running rough so I
replaced the bank 1 sensor 1.....yesterday I got the engine management
light and got a PO135 code for the sensor ... so the heater in the
sensor has gone....car is running fine I assume this will be an MOT
failure even though the car is running fine.....why the hell do they fit
heaters to these sensors just to gain some minor emissions crap until
the engine has heated up ?...

I've had a warning about my AdBlue heater for two years now. I believe the heater is broken, but since the freezing temp of AdBlue is -11C, I can live with that. My garage reset the code every time when they do an MoT.