[Kindfiend]

On a B13 ('92) if you unplug the O2 sensor while the motor is running... will that trip a check engine light or cause the car to change idle or any other effects??

Unplug it and see. The worst you would see is your car running rich. Like it hasn't warmed up yet. Just curious, but why do you need to know?

 

[Kindfiend]

Already tried the 'unplug and see' trick. I suspect my o2 sensor is trashed, but the ecu throws no codes, even if I unplug it. I think my car does run rich, I smell an abundance of fuel while it runs in the motor area. It never tripped the CE light, so I dunno if its supposed to and didn't, making me wonder if my ECU is jackked or what.

O2 sensors don't seem to always trip CEL's. At least on my 96 they didn't and they were both shot. My gas milage went from 25 to 35 after I swapped some new ones in. Other than that, I didn't notice any change in the idle or anything. Maybe a little better throttle response too... I doubt there is a problem with your ECU.