o2 sensor question

[aslee35274]

Hi guys I recently bought a cheap automatic 1997 Legacy 250T wagon to use as a run-around while down at university. Lately it's been stopping (stalling, i guess) randomly. Generally this would happen when pulling out of park, soon after I start her up, but there have been 1 or 2 times that it happened while travelling on the open road. I've noticed that it seems to happen more if the cars been sitting in the sun all day, or if I start it up when still warm, though that could easily be a coincidence. Other than that, the only thing I have noticed is some hesitation when accelerating.

 

When the check engine light came on, I pulled the code which indicated a faulty oxygen sensor. I've read in a few places that stalling is a possible symptom for faulty o2 sensors, though no where explained why? When I took it in to my mechanic today, he seemed pretty skeptical that that was the issue too, but I was wondering if anyone had any opinions or could elaborate on why a faulty oxygen sensor would cause a car to stall?

 

Cheers

[subikid90]

Your O2 sensor is used for A/F ratios when the car is at operating temperature. It is cutting the fuel on you when you stop.

[pqkillerAU]

If your o2 CEL is coming on, even for brief periods, it needs replacing. Something else may well have caused it to foul, or it is just past its usable service life. Either way, it needs to be replaced and see how the car runs then.

[spooln30]

Yes your o2 sensor could cause a running condition like that. If you have a cel for a o2 for circuit fault then replace it.