Two quick O2 sensor questions...

[Eddystone]

1. Where do the O2 sensor leads connect into the harness? Am I seeing them down near the heater hoses in my 98 V70 non-turbo?

2. Does the engine temperature sensor affect the computer's assessment of the readings of the O2 sensors? Is it a factor?

My O2 sensor issue seems to have disappeared since I replaced the temp sensor, though I may still need to put more miles or engine cycles into the car. Also, I handled those connectors down below the heater hoses and might have restored a bad connection. The down stream sensor was not showing a waveform, but now it is.

[Clemens]

1.) Yes, the O2 sensors should be connected into the harness where you described.
2.) no clue, sorry

[Eddystone]

Just took the car out for a 50 mile drive under a variety of speeds and conditions. Shut it off and started it a few times. Ran it on the highway at 70 mph. Country roads. Steep hills.

No O2 sensor errors. I suspect that there was a bad connection. May have to get down in there and clean up the plugs, one of which has some sort of oil on it.

[Clemens]

How old (years ot miles) are the sensors?

[scot850]

Coolant and air temp sensors will affect the way the car runs and therefore what temperatures they see, therefore the ECU adjusts for the input temperatures and thus what the O2 sensors see.

Neil.

[jreed]

I have read in a couple of places (one linked below) that the connectors on the O2 sensors are the source of the reference oxygen level in the atmosphere. I'm no sensor expert, but if I understood it correctly the air from the atmosphere travels up the insulation and into the back of the sensor to provide oxygen to the outside surface of the sensor. If the connectors gets contaminated with oil, it can block the oxygen and can cause the sensor readings to drift.
https://uk.rs-online.com/web/generalDis ... tors-guide