Oxygen Sensor Problems


#1

I have a 1996 Subaru Legacy L Wagon and the check engine light is on, indicating a problem. According to my mechanic, the codes in the computer indicated that the cause of the problem was a bad oxygen sensor. The oxygen sensor was replaced, but in a few days the check engine light came on again and indicated that oxygen sensor was still bad. I have also noticed that the car is not getting a good as gas mileage as it is supposed to. EPA estimates for the car is 23 mpg city/32 mpg highway. Right now it is actually getting a little less than 22 mpg and most miles driven are highway miles. Does anybody have any suggestions on what might be the causing the check engine light to come on and/or the poor gas mileage. Thanks


#2

The code is for a circuit malfunction. The computer is saying it is not getting good or reliable information from the sensor. It could mean a sensor replacement or it may be a problem in the wiring. A proper diagnostics should have been performed, not just a simple parts swap. To be fair, the parts swap works maybe 85-90% of the time. But, you should take it back, and have them fix it right.


#3

Just in case, go to Autozone and ask for a free scan, and give us the exact codes it lists. Maybe it accomplishes nothing, but it’s free.