I have an Altima 97 with 19k miles on. Recently, the yellow engine light
came on. I borrowed an electronic code reader which indicated that there was
a problem with an oxygen sensor. Then the light went out by itself, so I
thought this was just a glitch, but it came back on. Any ideas what this may
be caused by? If it is indeed an oxygen sensor, is it something I can fix
myself or do I need to take it to a shop? BTW, I don't know if this is
relevant, but the car passed the smog check a few months ago.

Thanks,

A

"a" <xxxxxxx (AT) pacbell (DOT) net> wrote in
news:dHFkf.36011$6e1.33631 (AT) newssvr14 (DOT) news.prodigy.com:

Sounds like mine.
There are two O2 sensors one before the cat converter and one after.
The scan tool should have told you which one was bad. I can also
read the sensor to tell if it is currently working. With the O2
sensor in-op the car will run in open loop mode. You may notice a
performance difference (mine pings).

Replacing the O2 sensor is relitivly easy. You will find it
stuck into the tail pipe just before of after the Cat converter.
Before you replace it, try cleaning the connector contacts.

As for the light going out. It will go out if no trouble is
detected for six consecutive trips.

Thanks for your reply.

I think it was the O1 sensor.


This may indicate that the sensor is not faulty, but there may be a bad
connection.

Thanks for the advice!

A

"a" <xxxxxxx (AT) pacbell (DOT) net> wrote in news:kfZlf.30113$q%.3422
@newssvr12.news.prodigy.com:

Sorry about the confusion: O2 = Oxygen.

#1 O2 sensor is in the manifold, #2 sensor is in the tail pipe
after the cat converter.