2000 S-Type V8

3 months ago I had my mechanic change out the O2 sensors on my Jag. For the past several week I have an engine light. when I run my scanner the error code is saying that I have an O2 sensor problem.

The car feels like it is going to stall in idle but runs fine and performs well otherwise.

Anyone ever experienced this issue? What do you guys think is my next move?

Thanks for any help and suggestions you can offer!

 

What is the code?

Why were the O2 sensors changed in the first place?

How much maintenance has the car had? Like changing plugs and coils and cam cover gaskets.

How many miles?
Have the timing tensioners been changed?
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+1 on what he said

 

88,000 miles - O2 sensors were changed because the OBD code called them out.

The car has had just normal maintenance unless an engine code was found so I am sure plugs and coils have not been changed.

 

You had codes that showed all 4 O2 sensors needed to be changed??

You are way beyond me. I have never seen that and I would be VERY suspicious that something different was going on. If you ever get anything that says it's all bad, look somewhere else.

4 O2 sensors don't fail all at the same time. Just all coils or all spark plugs don't fail at the same time.
Are you sure the repair place did not just change them all because they were not sure what the problem was?

Still need the actual code.
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Guys I appreciate all the help - Thank you!

I am not sure why but the OBD II reader that my parts store has does not show a code, no number no alpha code just what it thinks is the problem. I went back yesterday and heres exactly how the process went. He plugs it in to the OBD port, he enters the make and model it ask if its a 3.0 or a 4.0. He enters the info then it says scanning. The next screen shows O2 sensor 1 on sensor bank 1 is responding slowly.

Thats it guys, no numbers, no alpha, nothing but what I said. At least now I know whats up and can deal with it.

You guys are always great, thanks again!

 

Don't trust the code reader to interpret the code - they can be highly MY specific.
You need your own reader - many threads on this but a Bluetooth OBD dongle and an app called Torque running on an Android suits me.

 

+1
Get a nice crude OBD tool like an elm327. Really good value and does plenty. $15 for the USB, a bit more for BT.

The 2003+ cars have fairly advanced O2 sensor 1s (upstreams) and quite a few tools try to figure them out but get it WRONG. These O2s are linear (aka wideband aka UEGO/UHEGO). They don't swing around so silly tools think they're not working when in fact they are!

 

First anytime you get the codes scanned. Make sure they clear them all out before he unhooks the reader from your car. You want the problem to repeat before you try to fix it.
Maybe try another parts place? I know all the code readers will give you a number along with the description that you got.

If it's only one O2 sensor giving problems. Swap the sensors side to side. If the code changes to the other side then I replace the O2 sensor. If the same code comes back then something is causing the O2 sensor to throw a code. We are lucky in that all 4 sensors are pretty easy to get at on the S Type.
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To add... did the mechanic change out the O2 sensors with OEM direct fit replacements or those crap "universal fit" O2 sensors? If they used the "universal fit" sensors - good luck!

As the other guys already pointed out - never has any of us seen the need for all 4 O2 sensors to be replaced at the same time.

Sensor 1/ Bank 1 is the O2 sensor - passenger side right before the cat converter - but there could be other issues causing this.... as already pointed out.