When car next in for it's 12month service going to get both sensors replaced, one I know is not actually doing much from the error code I got from my local car tuners, he thought they were dodgy just from listening to the idle, which is quite lumpy and bubbly, it was showing as running lean. I believe this means it will be fooling the ecu into making wrong adjustments. So am hoping it will be running even better and faster when done ? This is why if I leave it idling for too long the engine light comes on.
" P1131 lack of H02511 switch-sens lean"
MR200 Stage 3 200PS