I had the reoccurring problem of my SES light turning on and off, took it in and had the diagnostics run, and got the error code for replacing the O2 sensor, which they did, and it stayed off for a while, but came back on about a month later, this time permanently. I was prepared to live with it, but the SES light is actually quite a bright, yellow light right at the top, and it's uber-annoying when driving at night.
The Service Dept said they had several Minis across several year models with this problem, and wanted to know if they could use my car to try and figure it out, and so they had me leave the car (Mini Cooper, 2006, manual XMSM) with them, and gave me a loaner for several days.

They got in contact with BMW-Germany, and finally chased it down to an exhaust system flange gasket, which is near the O2 sensor on one side of the catalytic converter, and when they replaced that, it finally cut off again.

Sort of makes sense, if the gasket near the O2 sensor is leaking, that you would get high differential readings across the catalytic converter, and they really don't have any way to tell if the actual gasket is leaking, so the closest error code that comes up is "Replace O2 Sensor".
I got it back and went on a raod trip, and have been driving it around for 4 days now, and so far, it hasn't come back on.

You might have your Service Dept check that out.

 

what code were you getting?

 

was that the bank one 02 sensor?... mine use to do that too after
the v42 update. was on/off for a few months, dealer checked the
sensor but nothing was wrong with it. I just lived with it clearing the
code with my scanner.

I did an oil change a few months after the v42 update and the light
has not turned on since. probably just coincidence...

but, i did remove and put back the mid-pipe when i did the Helix
short shifter... perhaps that did it.

 

My light came on yesterday on my 03 and I got scared

The engine compartment started making this rattling sound, propeller like but I don't know if thats me wanting to hear the sound due to the light!

Anyone got some advice?

 

^^ yep, get the light scanned. Autozone (if you have one in your area)
will do a free diagnostic scan for you.

OBDII scanners can be had for like $75. i use a Actron one and
can read and clear codes.

 

I had that sound it was a rock in the power steering fan and it went away after an hour or so. My light was the O2 sensor wire was too close to the sharp heat shield causing an unseen cut/short. wraped it with tape and moved it and no more light.

 

Hey, I just came back from autozone

troubleshotting p0326
ome brand obdii

 

isn't that a knock sensor fault?
i have replaced about 6 knock sensors this year so yours could be bad also.

*edit*
actually i just read your first post about the car making a rattling noise and then the ses coming on, did you experience any knocking from the engine? is your engine runing ok now? can you sheck the spark plugs and post pics?

also you may wanna start a new thread since you hijacked this one...

 

Was this at MINI of Charleston???

 

well its been a month and the light just came on again code P2270. so i cleared it and i'll be changing the gasket.Any others with the same code do something different?

 

My code was that the O2 sensor was "bad", which makes sense, sort of. Yes, this was Mini of Charleston (SC), and I understand they have several Mini & MiniS that are doing it.
Apparently any "leak" in the exhaust system will cause the O2 sensors to mis-read, and that's really the only sensor error message that it will trigger.

So, if your SES light is coming on, try to find the "leak" in the exhaust system; that could be what it is.

It's still off, so.........so far so good.