hello to all
ok after the car has reach operating temp the reading at x11
is 48%to 52% fluctuating back and fourth this is at idle. at 2000rpm the reading is from 16%to26% fluctuating back and fourth. at that rpm is this normal ??thanks

I'm not sure about the exact percentage but as long as it fluctuates you're good.

Test it, when it warms up and starts fluctuating, unplug the O2 sensor, where does the reading go? plug it back in, how far off is it?

xp

__________________
1985 190E 2.3L - a constant project.

Did you disconnect the thing on the left fender well? I can't remember what it's called. It has a vacuum hose and electrical connector. Leaving it connected can cause what you're seeing. Remove the electrical connector and check again.

__________________
2012 E350
2006 Callaway SC560