Just pulling into my driveway after work today, a CEL came on out of the blue.
I put the jumper in and checked the code, 01. Primary Oxygen Sensor.

Since there were no other codes thrown, is it safe to assume that the problem is solely a malfunctioning O2 sensor, and not caused by anything else? In other words, by replacing the O2 sensor, is there much reason to worry about "something" that caused it to malfunction the first time killing my new O2 sensor as well?

FYI This is a bone-stock D16Y7 with about 70k miles on it. Never had a single problem with it otherwise. Although, I have been noticing a degredation in fuel economy in the past few months (I'm getting about 230-250 miles/tank instead of the 300-330 I "normally get" ... and this was after replacing my PCV valve, fuel filter, all the usual suspects). Can I blame the poor fuel economy on a failing O2 sensor? Or could the O2 sensor burning out be a symptom of whatever is causing the poor fuel economy?

-a

 

O2 will most definitly cause you poor fuel economy. They really are sensitive and seem to fail very often.

 

Thanks, I'll replace mine today with a spare I have lying around and see how it goes.

-a

 

Well, I was GOING to replace the O2 sensor today. I have a spare one from my B16 swap that I'm GOING to put in, but the wires from the sensor to the harness were a little short, and I didn't feel like splicing. So I just reset my ECU, and the CEL went away. I drove around for 20 miles today and still no CEL. Think it could have been a fluke that I got the CEL in the first place? It came on originally right when I did a heel-toe downshift into first (LOL) at approx 10 mph.

-a

 

haha well it is common for it ot happen anyways hopefully it wont come back on