• Hello, so I bought my wife a 2008 mini cooper s to commute to school. The car has 85000 miles on it and is pretty clean. When I got it home I replaced a leaky vacuum pump. The new pump is holding with no leaks. I cleared an oxygen sensor code and ran it. All of a sudden it started running rough and threw codes po300 ,301,302,303,304 plus the po13e again. I have sprayed for vacuum leaks with no success. I checked all connections I see no issues. I replaced the oxygen sensor and still have a rough idle and misfires. I ran live data and oxygen sensor are at 1.3 each in spec. Any ideas what I may have hit or disturbed during the the vacuum install or oil change. Thanks

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Lavado, you are experiencing misfires in every cylinder. I'd suspect you have a timing issue. Do you have a good local INDY shop where you live?

Things that can cause misfires:

1. Bad spark plugs and or ignition coils
1.1. damaged electrical wiring from PCM to ignition coils or faulty PCM (DME in BMWs/MINIs)
2. Bad fuel injectors
3. Improper engine timing or engine damage
4. Too much water/methanol if you have one of those systems installed.
5. Insufficient fuel pressure

The odds of all four ignition coils, spark plugs, or fuel injectors failing all at once are extremely high ... like a billion to one. So I would focus on things that hit all the cylinders ... timing, fuel pressure etc.

Step one, check your fuel pressure, and report back.
Step two, run a compression check. If bad, perform a leak-down test. Report your results.
Don't worry about the O2 sensor at this point, fix your misfire problem first.

 

Thanks for the response! Yea I am thinking timing or vacuum. Fuel pressure is around 7500 and the codes have not come back in 2 days, but the idle is horrible. The valve cover is leaking, but I sprayed it and cant get a reaction from vacuum. I'm planning on pulling the cover to replace gasket I guess I will look at the timing chain components then. The weird thing is the vacuum pump was leaking and I replaced it, then it seemed the idle was worse, swapped old pump back in to see and it made no change. Just ironic I guess...