Change Oxygen Sensor ?

[RageCage]

Hi,

I've had a few people tell me I should change the O2 sensor in my 85 Caprice with the 305. I have 368K on the car now and the O2 sensor is the original. Never had the check engine light come on. I get 18 mpg going back and forth to work, mostly long stretches of back roads. Seems pretty decent mileage for an old V8. The car runs fine. But some people have told me that old O2 sensors make the carb run rich, which wastes gas, and tends to overheat the cat, and clog it up.

The O2 sensor is only $20 at AutoZone, for a Bosch, and it looks easy enough to change. On the other hand "If it ain't broke, don't fix it".

Anyone out there changed the O2 sensor? Did it improve performance ?

Thanks

['97ventureowner]

I remember seeing a post concerning O2 sensor replacement and the resulting improvement in fuel economy. Here is the thread that the post is in:http://www.automotiveforums.com/vbul...=oxygen+sensor Read the last post in particular, (by 93buicklesabrelmtd,) for some info to help you make your decision.

[burnM]

If you do decide to chage it, go with O.E. if at all possible. I've heard that the Bosch sensors and other generic brands go bad real fast. Change it while the pipes are still hot, it'll be easier to get out.... just be careful not to burn yourself.

[CD Smalley]

The last AC-Delco packaged o2 sensor that that I bought had Bosch stamped in it....

But I do recommend you change it.

[RageCage]

Thanks for the replies. The car has been running great lately, and I don't know why, since I haven't done anything to it ! It has more power, and seems smoother, and a knocking sound has disappeared.

Yeah, the OEM O2 sensor is $ forty something, which is a lot, imo. I think you can test the O2 sensor using a multimeter though. If it tests OK, I won't have to risk breaking it off when I remove it. I assume you can leave it in the manifold while testing it.

Can anyone help me out with testing the O2 sensor ?

Thanks,
RC

[Morley]

Originally Posted by RageCage

Can anyone help me out with testing the O2 sensor ?

Thanks,
RC

Never heard of any way to ohm out an O2 sensor but you could try hooking a digital volt meter from the pigtail to ground while the engine is running in closed loop. You should see the voltage swinging from around 400mv to 600mv give or take 100mv or so...It should be swinging above and below 500mv.