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Stock Problems/IssuesDiscussions related to warranty related issues and repairs, or other problems with the OEM parts and software for MINI Clubman (R55), Cooper and Cooper S(R56), and Cabrio (R57).
I have a 2007 R56 S w/ 64,000 miles on original motor. When I start the car (cold or hot), it begins to idle at 1K RPMs, but immediately starts to bounce between 1,000 and 1,500 RPMs (see vide).
My wife did borrow my car and filled it with regular gas instead of premium. The rough idle started about 30 miles after she filled up an empty tank with regular gas. I know regular gas has an effect, but didn't think it could be this drastic. I put a bottle of Chevron Techron in the tank when she got home.
I drove it for about 10 more miles (on top of the 30 my wife drove) to get the check engine light to finally come on. I then took it to O'Reilly's and was given the following two codes. P129D (MAP Sensor) and P2096 (O2 Sensor). Which should I replace first, I'm hoping it's just one that is bad and that I don't have to replace both. Perhaps something else is wrong altogether, which is what brings me to you guys seeking help.
I've also uploaded a picture of my spark plugs which were changed about 15,000 miles ago. Based on the dry, dark look, it appears I'm running very rich. Does the O2 Sensor replacement fix this?
Last edited by wsdivall; May 27, 2018 at 04:06 PM.
Bad 02 sensor definitely can cause the car to run rich but running rich can also kill the 02 sensor and throw a code. But I'm going to put my money on the 02 sensor and the map/maf code was just a pending code.
Bad 02 sensor definitely can cause the car to run rich but running rich can also kill the 02 sensor and throw a code. But I'm going to put my money on the 02 sensor and the map/maf code was just a pending code.
I thought the O2 Sensor just monitored how much unburned oxygen there was and only notified the computer system if it was running rich or lean. I wasn't aware that it could make it run rich or lean.
PROBLEM SOLVED: I was digging around my motor looking for potential air leaks or broken plastic anywhere that might cause bad oxygen/fuel mixture, thus causing my O2 Sensor and MAP Sensor CELs. as I was doing this, I noticed the Solenoid connect was about to fall off completely. This is a cable that snaps in and I have no idea how it would have come loose like that during normal drive. I do recall back in October 2017 I had to replace my water pump and would have needed to disconnect that cable. I'm guessing I didn't seat it until it clicked tight.... and over time it wiggled itself loose. No idea, but we're back in action and idling smoothly. Thanks for any and all feedback.
I thought the O2 Sensor just monitored how much unburned oxygen there was and only notified the computer system if it was running rich or lean. I wasn't aware that it could make it run rich or lean.
Glad you found the problem! Just to add to this statement here though, you were partly correct. There are two O2 sensors - one upstream of the catalytic converter and one downstream of it. The upstream sensor is used to help the ECU hit the AFR it wants (wideband sensors let the engine hit any AFR, not just stoich), and the downstream one is only for monitoring the catalyst efficiency. So you are right about the downstream sensor, just not the upstream sensor.
