Threw CEL P0130 (Front O2 Sensor) after changing plugs

[cmags]

Hah, I've been a member for almost a year now, and this is my first post! :lol:

Anyway, my fiance has an '02 Legacy L sedan, and I just did her 60k service (at 65k), and after changing her plugs - using Autolite AP3923's (stock equivalent) she threw a CEL once the engine warmed up. Had the code pulled - P0130 - Front oxygen (A/F) sensor circuit range/performance problem (lean), reset, and it went away for about a week, then showed up again yesterday. Got it cleared again, and it's not yet back.

Could this be an issue with the plugs? Or just a strange coincidence that the O2 sensor would die (at 65k) at the same time I changed the plugs (which I had to remove the battery and therefore reset the ECU to do)?

Thanks a bunch!

[pdawg]

That code reads as follows : Front oxygen (A/F) sensor circuit range/performance problem (Lean).

I don't know if that tells you anything or not.

[cmags]

...Had the code pulled - P0130 - Front oxygen (A/F) sensor circuit range/performance problem (lean)...

I've already got the CEL code list and included that information in my original post. Typically that code means that the sensor is going bad. Thanks anyway, but I was looking more for someone having had this issue before with possibly a different explanation.

[Huffer]

If the sensor is reading a lean fuel mix, what the possible reasons for a lean mix?

[cmags]

OK, so this CEL keeps coming back after about a week or two after clearing it. Seems like it might be a dying sensor but I'm not sure. Either way, I was looking into replacing the sensor, and I can't seem to find the front sensor for sale anywhere. I see NGK 24598 and Denso 234-4132 (OE identical) and Denso 234-4212 (universal) sensors all saying that they're the rear sensor. Is there a difference between the front/rear sensors? I've got the factory service manual, but it doesn't give a part number for either, just how to replace them. The drawings look like the sensor is the same, but I'm not going to buy one that says "rear" for the front based on an illustration... :-?

So does anyone know if the front/rear O2 sensors are the same?

Thanks

[ivwarrior]

I don't know if the sensors are the same or not. Your problem is likely 1 of 2 things. Either the sensor is going bad, or just as likely, if not more, you've got a vacuum leak somewhere. Go over all the vacuum lines and make sure you didn't accidentally knock any loose when you were changing the plugs.

[Plays_with_Toys]

did you gap the plugs correctly?