O2 Sensor Question

[steveb]

Recently, my '85 was running rich due to a problem with the fuel pressure regulator. Although I've got it running again, the performance seems to be suffering. Can a rich running engine ruin an O2 sensor? After putting everything together, I drove it for a good 1/2 hour and no codes were thrown. But I did notice performance was suffering and mileage didn't seem as good. Thanks in advance.

Steve

 

[Galen]

Unhook the battery and then reconnect it after a few minutes. That will clear its memory then it will relearn with driving time.

Galen

 

[69MyWay]

It might not hurt to remove it, spray it down with brake cleaner or carb cleaner, then lightly burn it off clean with a propane torch.

You may have other issues.

Just because there is no code, does not mean you are 100% healthy.

You need to determine if it is going into closed loop.

Do you have a scanner?

You can ground out the diagnostic terminal and run the car in field service mode. The blinking of the check engine light will help you determine if you are rich or lean.

Get a GM service manual on the car. There is some great reading in there on the subject of accessing your computer and getting a feel for what is going on.

Good luck!!!!!

 

[Robertwav1]

I remember from some earlier GM cars that it takes the computer a good 100 miles before everything rights itself after a battery disconnect. Rough idle or slight surging shoud disappear.

 

[vader86]

A bad O2 sensor will cause a rich-running engine, and a bad MAF can also screw it up.

Its likely the O2 is the culprit.

 

[steveb]

Thanks for all of the replies. The O2 sensor doesn't appear to be too expensive and I am pretty sure it is the original. I will probably go ahead and replace it to eliminate it as a possibility. I do have the shop manual and will go through it as well and check out some of the diagnostic procedures. It looks like I might have to wait a while to go for a drive. The snow is flying here in Illiniois. Thanks again.

Steve