o2 sensor

[ecnar]

My mom has a 99 contour 2.0 with 37,000 miles on it. She recently had a catalytic converter replacement ( 2 months ago). Now the check engine light is on. I took it to Autozone and they retrieved a code for failure in both O2 sensors. Could this be related to the cat replacement? I did not know she was having this done. 37,000 seems early for a cat replacement unless they were clogged. The cats were replaced under warranty. Also, are the sensors easy to replace on my own?
Thanks,

[JoeShmoe]

They will go bad very easily if they are exposed IIRC. When I replaced my mufler mine went out to in a matter of days. Its very simple to change them out, because you have a 4 cylinder, the upstream one is going to be in the header somewhere, usually beside the oil filter in this car. The downstream one should be after the cat about 2 to 4 feet away from it. Just make sure you have enough leverage cause thos e babies are very hard to loosen.

[beyondloadedSE]

O2 sensors wont go bad by exposing them (I'm assuming you meant to ambient air). If that were the case, they would go bad as soon as you took them out of the box. Things that can cause your O2 sensors to wear out more quickly would be like running high octane race fuel or dropping them on the ground.

What was the code exactly? I could see both O2 sensors throwing a rich or lean code at the same time since thats what they are designed to do, but for both sensors to throw a "slow response", "high voltage", "out of range", or "circuit fault" at the same time seems a little unlikely. My guess is, you were throwing a rich or lean code and the mechanic told you to change your O2 sensors.

[ecnar]

The codes are P0132 voltage from oxygrn sensor 1 in bank 1 is too high, and P0141 malfunction in heater circuit for oxygen sensor 2 in bank 1. The AutoZone employee suggested replacement of both sensors.
Thanks

[JoeShmoe]

Originally Posted by ecnar

The codes are P0132 voltage from oxygrn sensor 1 in bank 1 is too high, and P0141 malfunction in heater circuit for oxygen sensor 2 in bank 1. The AutoZone employee suggested replacement of both sensors.
Thanks

Yes you definitely need to replace them both. I meant if they were exposed after being on the car for a while. When they are in the box, they have a coating.

[beyondloadedSE]

You may have to replace them.

What I would do first is disconnect the battery for a couple minutes to clear the codes and see if they come back. If they do, then replace them.

[ecnar]

I just noticed that the blue connector going to the 2nd o2 sensor on the exhaust pipe was disconnected. I am hoping this was the problem. Unfortunately, the connector was dragging on the ground and was worn down and cannot be used. Is it possible to get a replacement connector? Or, can I splice the wires? Is it possible the mechanics who worked on it recently forgot to plug it back in? If so, I think they should replace it.
Thanks for all the help. Also, the catalytic converter was in December not 2 months ago as I previously stated.

[JoeShmoe]

I think you can splice it together without a problem.

[gtmud]

If you splice the wires, you had better soldier them. any resistance in the connection will give you false code issues. Never be quick to change the o2's, for one they are to expensive and two are not that likiely to go bad. Check everything and if you can get the car on a scan tool that will show you exactly what is going on with the engine running.