Hi guys. 07 S hardtop r56, n14 with 90k miles. I've been getting the yellow engine light and with my cheap bluetooth code reader and torque app I get P0141 and P115c fault codes. engine seems to run ok. looks like the P0141 is bad oxygen sensors. these are like $100 at least, each. I found some cheap ones on rockauto and ebay. anyone try these cheaper ones? if so, can you link me what you're using.

is there anything else I should look at? maybe its not the sensors?

thanks.

 

Don't go cheap! Not all O2 sensors are the same. The MINI needs NTK sensors. I installed a Bosch pre-cat O2 sensor from Rock Auto, and found out that while it is listed as the correct part for the car (N12 engine in our MINI) it isn't. Ordered/installed the NTK pre-cat O2 sensor, and MPG went up by 10.

My local Indy shop owner said he only uses OEM supplier sensors.

 

you only replaced one sensor? how did you know that was the bad one? I read they should both be replaced cause the other one is likely to go bad soon after.

 

Yes ... the pre-cat sensor. The old sensor was still good. I had the cylinder head off due to it being warped; I found a cylinder leaking on a leak-down test.

As always, be careful what you read.

 

my engine light went off. I think it has something to do with the humidity or outside temp. more humidity triggers the light I think. I'm debating if I should replace the sensors or see how long they last. is there damage being done? like more carbon buildup?

 

If O2 sensors are failing you are wasting gas, which is money = pocket damage.

 

With my other cars -- the JCW has been CEL free thank goodness -- they manifested a few CEL events due to O2 sensor errors. Not one was caused by high or low humidity (driving through Texas down pours or desert single digit humidity) nor temperature extremes and I drove in 0F to 119F temperatures. (In some cases I drove half way cross country going from near triple digit temperatures around the CA/AZ border to below freezing in Flagstaff, AZ -- this in around150 miles of driving -- back to very high temperatures (and humidity) as I drove east and to lower elevations and south into mid Texas and some of the heaviest rain I've ever experienced.)

The sensors should not collect carbon.

The odds are the problem is intermittent but still due to a bad/going bad sensor.

What you can do is clear the error codes -- even if the CEL is dark. This clearing the codes resets all the learned values to their defaults. Then just drive the car normally. If the CEL comes back on read and write down the error code or codes: There will be an active code, a freeze frame code, and maybe a pending code or more, and possibly even one or more permanent codes. The permanent codes are codes only the engine controller can erase after so many warm up cycles with the error absent.

The problem suggested by the active/freeze frame code that is what you should focus on.

 

I replaced the two oxygen sensors last night with ntk sensors. cleared the codes and drove the car today for like 45 min total and checked for codes again. found a pending p115c code. last time I got this code I cleaned the maf and I believe it went away. if the car was running rich because of the sketchy o2 sensors, what stuff should I look into cleaning that has to do with that code?