Odd O2 Readings?!

[tom04841]

I have my SAFC hooked up to monitor my 02 voltage. IT doesn't sweep at all, just climbs steadily to .6? volts. I have tried swapping 02 sensor out, with no change. Any other ideas of what the problem may be?

 

[DSM90AWD]

The S-AFC "blue wire mod" is known to produce erroneous O2 readings. I tried it myself 5 years back and got lower than expected voltages.

You may want to double check the output by using a datalogger or automotive multimeter.

Also remember that the O2 sensor voltage will fluctuate only when in closed loop operation (i.e. during cruise or idle).

 

[daren_p]

I'm not using the safc but before I got dsmlink & was looking at it, I remember reading somewhere (rre or vfaq I believe) that it wasn't a good idea to hook up the safc to read your O2 voltage because it puts too much of a load on the circuit. I believe you need to hook up an amplifier or voltage follower circuit to work properly (can't remember what its called).

 

[tom04841]

Even with the safc disconnected it is still doing the same thing. It wont cycle.....just stays steady...i checked it with a multimeter. Throwing o2 sensor code as well, but replacing the sensor does nothing. i checked the wiring from the sensor to the ecu, and it is fine. WTF

 

[tom04841]

replaced the 02 sensor today. No difference....well instead of staying steady at .6v, it is now steady at .9v. it only changes when i rev it up and let off. What is going on anyone?

 

[TotalEclipse112]

Try looking for an exhaust leak before the o2 sensor, an exhaust leak can cause that to happen.

 

[tom04841]

i have a small crack in the manifold and one bolt on the 02 housing is broken, but i cant feel anything getting by. you think that might be it?

 

[TotalEclipse112]

Sure could be try to replace the bolt in the o2 housing first. Very rarely to cracked exhayst manifolds leak. But a missing bolt on the o2 housing might be just enough of a leak to throw the sensor off.