Trying to run down an 0420 CEL. Does anyone know what the readings should be on the O2 sensors?

 

I'd like to eliminate them before I start replacing converters.

 

Also, any recommendations on scanner software would be appreciated.

do a search. some one recently, last few weeks, had a thread with good detail about testing an o2 sensor.

 

what i remember is the voltage on the sensor signal wires was low, real low and fluctuated between or within 2 values as it read the exhaust?

 

if any one remembers who posted it or a key search phrase that would help.

 

do a search.

my recommondation is to just live with it. Ive had a 420 code and cel light on for the better part of two years now, tried O2 sensors had a used cat put on and still have the code. Car runs just fine, light is a little annoying but then again so would the grand id have to fork out for a new cat. Unless you have to pass an emissions inspection just live with it, this has been my experience and also the advice of some pretty knowledgeable mechanics. BTW mine is a 2000 legacy wagon with 180k.

 

Tim

In PA the cel will fail you at inspection time.

do a search. some one recently, last few weeks, had a thread with good detail about testing an o2 sensor.

 

what i remember is the voltage on the sensor signal wires was low, real low and fluctuated between or within 2 values as it read the exhaust?

 

if any one remembers who posted it or a key search phrase that would help.

 

do a search.

 

Yeah, tried that. Found a link to an article, generic in nature that gave only relative values, and nothing specific to our cars.

I got my code reader from Sears recently for $50. My light was intermittent so I reset the light before I pulled into the emission station here in MD. It passed. I still get the intermittent light with varying codes. still have the fluctuating idle and stumbling occasionally. btw... 99 2.2 legacy auto with 226,000 miles.

did you see this one??

 

http://www.ultimatesubaru.org/forum/showthread.php?t=66744

That link has a good discussion on testing O2 sensors.

I am still looking for some recommendations on scanner software.

 

maybe I should start a thread with that title.