O2 sensor

[LazyDog]

Looks like an ELD is $36 off Amazon. Guess I start there, although I wouldn't mind scoping the 12V line first. From what I can tell, a bad ELD should trip a code of its own.

I try reading my son's CRV w/ 3 different scanners low end scanner nothing, Bosch yes, Matco yes for ELD code but no check engine light.