oxygen sensor

[michaelburns24]

Hello, my check engine light came on on my 89 ranger 2.9L pulls code 41 which says
hego (ho2s) sensor voltage low/ system lean
hego (ho2s) sensor signal out of range/ always lean
No ho2s switching detected

I replaced the oxygen sensor, and cat 2 months ago, only drove about 6 miles, and had to replace the heads, since then I have only driven about another 10 miles. could the oxygen sensor have gone bad already, or is there something else that could be producing that code?

Also on cylinder balance check it says there is a problem with cyl 6, plug looks a little black on 6, the plug wire is new, and the compression is good
any ideas?

 

[MAKG]

ANYTHING that gives you low voltage (including actual excess oxygen such as from a vacuum leak or a miss) can trip that code. A bad sensor is only one way of many.

It's not an easy diagnosis because there are a lot of possibilities. But make sure your entire feedback circuit is working. Quite a lot of people ignore wiring, yet it's a very common fault. Is the voltage just low at the PCM or is it low at the sensor as well? Do they agree?