1991 240sx: what voltage should oxygen sensor read at idle

[vancouverbc]

I always get something around .9 volts which by any definition or not. Maybe it is supposed to be on the rich side at idle.

[NISTECH]

It will very but most nissans lock lean at idle [low voltage] If its always at .9 thats a bit unusual and indicates it has a very rich idle. Might want to start looking at your ecm grounds,airflow grounds and such. Be aware any checks you do on the o2 should be done with the car fully warmed up since during warm up the car normally does run rich.

[driftingmy240sx]

i agree with nistech. normal idle volt from an o2 on most nissans is .2-.4 volts. check your grounds, check the maf, i have also see failed o2's do this.