Micra K12 2004 Running rich

[james125]

Hello everyone.

My sister has just had here Nissan Micra K12 2004 1240cc petrol model fail it's MOT on the emissions, the car itself is well maintained regular services and sub 100k.

1st Fast Idle

CO 0.95% max is 0.2%

HC 277ppm max is 200ppm

Lambda =0.97 (min is 0.97)

2nd Fast Idle

CO 4.8% max is 0.2%

HC 849ppm max is 200ppm

Lambda =0.83 (min is 0.97)

Natural idle

CO 0.57% limit 0.3%

It's also developing blue smoke, on acceleration. I'm guessing that one of the lambda/oxygen sensors is broken. Which would make it run rich, which would fill the oil scraper rings with carbon thus burning oil. But the problem is there are no diagnostic errors on the dash. I wondering if I should purchase an OBD scanner and take a look at the faults (if it has any). Or perhaps I could test the lambda sensors with a multimeter? Is that possible? Where would you start guys?

Thanks!