I REALLY need help…Please!!! My daughter has a 2008 Mini Cooper and I have spent $2-3,000 (at the minimum) over the past 5 years having the Oxygen Sensor replaced. She made a trip to Nashville to school 2 weeks ago and it happened again. ( the car runs rough, stalls out under 1,000 rpm and the check engine light is continually on ). She called me about 30 miles NW of Nashville and it had happened again. So, long story short, I stayed on the phone with her until she got there, we had a relative recommend a foreign car mechanic, he called me the next afternoon and said, "David, they’ve been putting the wrong 02 sensor in this car. At last…the problem solved! She drove to Milwaukee Monday and started home today…about 10 miles North of Springfield, IL it happens again!!! I had her drive to an Enterprise Car Rental, get a car and she’s on her way home now. Problem is Wednesday I have to drive that rental car back up there and pick up her Mini Cooper. I have no idea what to expect!! I’ll try to make it home to Central Missouri. ANY advice you can give me on this issue would greatly be appreciated. I have no clue what to do. Many thanks. doccollins93@att.net. I’ll also check back on this post.
[2019-04-29}
There’s only two things I know of that will kill O2 sensors.
Those are coolant leaking into the engine, or someone used a sealant on the engine that isn’t sensor safe.
Tester
11 year old car with a known reputation for problems. What you should do is fix it one more time and trade that lump.
What makes you think it is an O2 sensor problem. Do you have an engine check light on? What is the code, if yes?
If the shop is replacing the O2 sensor just b/c there’s an O2 sensor code present, try to find a more experienced shop, one that works only on European cars. This problem needs to be properly diagnosed. O2 sensors are non common failure items. When they do fail, it is usually the sensor’s electrical heater, not the part that senses the O2 concentration. Of course when they’re replaced they have to be replaced with a compatible part. It would be very unusual for a shop that works exclusively on German cars to install the wrong part number.
There’s many things that can cause O2 sensor codes, from wiring problems, unmetered air leaks into the engine, exhaust system problems, fuel system problems, air intake problems, egr system problems, pcv system problems, turbo problems, and ignition system problems. To get much in the way of help here for this problem you’ll have to post the actual diagnostic codes.
One thing to be cautious about, if the O2 sensor code is indicating an overly rich fuel/air mixture, driving the car with that problem could damage the catalytic converter, very expensive to replace and best avoided. If you have that problem best to have the car towed to a shop. An overly lean mixture could cause engine overheating, another caution.
Thanks so much for that information!
Thanks very much for the response. The four times that this is happened have all been when my daughter is out of town at school at cetera. When each shop did the Diagnostics on the car they got the code that told them the O2 sensor is bad. That’s just what I’ve been told and man has it been expensive and not worked. Please tell me what you think
Without knowing the specific fault I can only guess that there is a lean system fault because of a failing fuel pump. Sometimes fuel pumps become weak after several hours of driving and deliver an insufficient amount of fuel, the result is poor performance and a lean system fault that some believe is an oxygen sensor fault.
Without duplicating the problem one can only speculate what the problem was but reviewing the faults and freeze frame data would put an experienced technician on the right track.
Thanks very much! That makes sense!!
There aren’t any diagnostic codes which specify the O2 sensor is faulty. That has to be determined by subsequent testing. Codes referencing the O2 sensor only indicate the engine computer isn’t able to resolve the discrepancy of the O2 sensor reading compared to the other sensor’s readings.
The shop that is diagnosing this problem will be heavily relying on the fuel trim data I expect. If, along w/the diagnostic codes, you post the fuel trim data, folks here may be able to offer better guidance. Mini’s have a bit of a reputation of being hard to diagnose, so it may be your shop just needs to have a few more goes at it. Patience is required when diagnosing Mini engine problems. You could use the forum search feature to see other threads about Mini’s we’ve had here. Upper right on this page.
Welcome to the world of Cooper.
Thanks so much. Very helpful!
You seriously need to find a better caliber shop
One that knows how to think logically, diagnose, and not just fixate on fault codes
The symptoms don’t point towards the oxygen sensors, in my opinion
Did the guys at the shop even duplicate the problem?
If so, did they then drive with the scanner hooked up, while they were monitoring various pids . . . ?
I suspect they focused on the codes, to the exclusion of many other possibilities/probabilities . . .
One thing’s for sure, in any case . . . the mechanics you’ve been using don’t know the term “verify the repair” 
Thanks much!
Hi Tester,
I see that you’ve commented and helped on a lot of these posts related to the O2 Sensor. I am wondering if you can help. My check engine light comes on for a while, then turns off for a bit and returns soon after. I took my car to a mechanic, changed the O2 sensor, ran it for some 60+ miles and again, it came on, turned off but I took it to the mechanic anyway. He says the code reads as pending so that he needs to do more work on it to figure out the problem or tha maybe that the replacement O2 sensor was faulty itself. Do you have any idea what this could be?
Instead of attaching your question to an over one year old post, start a new one.
Avoids confusion on who’s answering which question.
Tester
Make, model, year, miles etc. would help too.