I'm throwing multiple non-permanent OBD codes saying, O2 sensor malfunction (bank1 sensor 1). I also managed to get a good puff of black smoke and heard a slight hiss and the car sounds like it is running lean. Light came on just before some planned brake work so while the MINI was on jacks I had alook around and noticed my O2 sensor before the pre-cat had some nice shades of green, from heat, much unlike the sensor after the cat. converters also I've had issues with a connector to that sensor staying tight, threw and O2 sensor circut malfunction pushed it tight and that went away and seemed nice and tight when the code went on today. I cleared the codes and did some driving no issues, had this code in combo with other electrical issues one as a spontaneuos spaz for about 5 min. Any ideas? Anyone seen this in their MINI before?
p.s. I'm runnung all stock except the ALTA CAI.

 

mine use to give that code after doing the v42 recall a couple of times. just an error message. lately i haven't gotten it.

 

I read a post about you getting on occasion when nothing was wrong, I thought I had the same issue but then it sound lean the past few weeks and sound like there may have been a leak last night , plus the puffing somke out the back I'm thinking I may have a more serious issue. Have you seen the sensor since you had the code, if so how does it compare to the second O2 sensor?

 

Sounds like an air leak to me. Codes which point to O2 sensors seem to
often mean that the ECU is unable to adjust the mixture to get the O2
sensor to read in range. Sucking air somewhere causes the mixture to
go lean. The ECU tries to enrich it to compensate and you get a rich
mixture which causes the exhaust smoke.

 

So how should I go about finding and fixing the leak? Is this the point were I have to make a trip to the dealer?

 

^ i'd first see if any of the bolts/nuts are loose on the piping.

 

Yeah you might have an airleak somewhere...I'm assuming that this is pre-cat O2 sensor from your descriptions. Check your manifold for leaks where it bolts onto the head as a leak here can cause problems as there's no actual air going into your motor, but DME thinks there is so will add more fuel, getting a very rich mixture. Also if you did a VGS, you might want to check that out...Beyond that, take it to the dealership I guess :\

 

A piece of hose works great. Just put one end in your ear and move the
other end around the engine (idling). You'll hear it when you get near the
source of an air leak.

 

Well the light popped back on tonight, so I think I'll leave the light on and just take it to the dealer and let them fix under warranty. I also got the O2 circuit sensor malfunction coe, and the engine did not cool down at any where near as quickly as it usually does, 1/2 hour of being off, the engine didn't cool at all.