Hi

Passes emissions at fast idle and O2 sensor switching normally, at normal idle O2 sensor stuck at 0.8v CO = 1.4%.
If headlights and other electrical loads are turned on then O2 sensor switches normally at idle and emissions are good.
I have run separate earth from O2 sensor grey wire to battery earth but still sticks at 0.8v, no electrical loads on.
Any idea why the electrical load helps here?

Thanks, Martin.