Greetings!

I am the proud owner of a 2010 MINI Cooper Convertible with almost exactly 70000 miles.

A few weeks ago, I started her up and was greeted with the dreaded check engine light. My MINI seemed to be idling a bit rough, had somewhat reduced acceleration (it was reeeally cold, though), and was producing grey smoke out of the tailpipe. I motored on over to Autozone and had the codes read. I have three codes: P0302, P0304, and P2195. I purchased and changed the O2 sensor as well as changed the spark plugs on cylinders 2 and 4. I started her up again to find that the check engine light was still on. I disconnected the battery for several hours and started her again to find it still on. The OBDii reader shows the same errors. The car is still idling a bit rough (but seems to be running well once warmed up) and I'm still getting grey smoke (again, until warmed up). I've only driven about 10 miles since the repairs and all driving has been under 40 mph or so.

Any clue what I should try next?

 

Maybe an oil leak of some type with oil contaminating cylinders 2 and 4? They make smoke. Maybe valve issue? Whats the smoke smell like? Clogged pcv valves can cause smoking too. Oil in exhaust can cause 02 sensor issues.

 

Hmmm...the smoke smells strongly of exhaust. (Sorry, I might not be understanding your question correctly.) I did notice that there was oil coming out of the tail pipe immediately after the O2 sensor change. I was hoping that it was just built up gunk being pushed out.

 

If you shut it off briefly, like a few minutes does it still smoke on start? Is the smoke blueish? Does it smell like old oil from a deep fryer or does it smell more sweet like coolant? If its puffy white smoke thats usually water based, blue is oil. If its only after sitting overnight when cold and does not come back in 20+ minutes it may just be condensation but that would not trigger codes. Are any fluids low? Oil? Coolant?

 

I recommend that you tackle one thing at a time. It is likely that the P2195 code is being caused by the misfire codes. The smoke is probably due to the misfires on 2 and 4. I suggest that you swap the coil from cylinder 1 with the one on #2. Then get the codes read to see if the fault went to #1, the code would then be P0301. If it does then do the same with 3 and 4. If the error move then you have two bad coils.

 

It doesn't smoke at all once it's been warmed up. Actually, when it's warmed up, it seems to be running fine. The oil seems a tad low. I haven't checked the coolant, though.

 

We swapped the cylinders last night, brought it to Autozone, and had the codes re-read. Here are the codes from last night:

P0300-Random/Multiple misfire detected
P0302-Cylinder #2 misfire detected
P2195-O2 sensor signal stuck lean bank 1 sensor 1
P0301-cylinder #1 misfire detected
P2195-O2 sensor signal stuck lean bank 1 sensor 1
P0301-Cylinder #1 misfire detected
P0137-HO2S (Bank 1 Sensor 2) cirucuit Low Input
P0304-Cylinder #4 misfire detected
P15E8


We swapped the cylinders back to their original location, drove it at ~60mph for 20 miles this morning and had the codes re-read again. Now we get this:
P0300-Random/Multiple misfire detected
P0302-Cylinder #2 misfire detected
P2195-O2 sensor signal stuck lean bank 1 sensor 1
P0301-cylinder #1 misfire detected
P0300-Random/Multiple misfire detected
P0302-Cylinder #2 misfire detected
P2195-O2 sensor signal stuck lean bank 1 sensor 1
P0301-cylinder #1 misfire detected
P0304-Cylinder #4 misfire detected

This is copied from the printouts that I was given at Autozone. I'm not sure why some of the codes appear more than once on a single read.

I'm beyond confused.

 

I notice that you also have a code P15E8, This is what I found:

* MINI DTC P15E8 (0x3392) - Engine shutdown time, plausibility: Time too short relative to temperature drop in engine coolant
The diagnostic function monitors the engine's calculated downtime by comparing it with the drop in coolant temperature while the engine is stationary.
The time required for engine cooling is implausibly short relative to the calculated time.

Potential problem source(s):
- Instrument cluster disconnected from Terminal 30 during stationary phase (battery change)
- Collateral fault stemming from a defective engine temperature sensor
- Collateral fault from incorrect time signal from the instrument cluster

If the temp sensor was bad, this would explain why the car runs well when warmed up. I hate throwing parts at problems, but I suggest you start with that.

Have you had any issues with your battery, a weak battery can also cause problems with modern cars.