Emissions Problem -2009 Mini Clubman

[neepheid]

My daughter's Mini Clubman has just failed its MOT on emissions. I had a look at the emissions printout, and was amazed to see that CO was over 8%. The limit is 0.2%.

My question is whether a car can run smoothly at that level of CO? The car passed emissions 12 months ago with no problems, and hasn't been used much since, maybe 3000 miles. The car has high mileage, 168,000, but runs very smoothly, idles evenly and fuel consumption isn't excessive.

I have seen such a high CO level in any of the many cars I have owned over the years, and some of them were real old bangers. I'm wondering if the MOT station's exhaust analyser is faulty?

[350Matt]

I'd bet its burning oil like a good un with that sort of reading

[Challo]

neepheid said:

My daughter's Mini Clubman has just failed its MOT on emissions. I had a look at the emissions printout, and was amazed to see that CO was over 8%. The limit is 0.2%.

My question is whether a car can run smoothly at that level of CO? The car passed emissions 12 months ago with no problems, and hasn't been used much since, maybe 3000 miles. The car has high mileage, 168,000, but runs very smoothly, idles evenly and fuel consumption isn't excessive.

I have seen such a high CO level in any of the many cars I have owned over the years, and some of them were real old bangers. I'm wondering if the MOT station's exhaust analyser is faulty?

Could the lambda sensor be faulty?

[neepheid]

There is no smoke, or signs of burning oil. The Lambda sensor is a possibility, but there is no engine fault light showing. All a mystery. I'm borrowing a fault code reader tomorrow to see if anything shows. Then I'm going to get the emissions tested at another garage. I just can't believe that an engine with 8% CO would start, never mind run smoothly.

[350Matt]

Pull a spark plug out if its really 8% CO its will be sooty black