E34 540i Mot fail help

[goatboy]

Just put my car through its MOT and it has failed horribly on CO% 0.82 for 0.30 limit. I gave the car to my BMW specialist who had a look at it but essentially said that they did not know what was up and I needed to speak to an electrician. I am duly booked in but wondered if anybody has any ideas for me. Car only has 100k on it with full history but I have a nasty feeling this will be expensive to put right. Bugger it!

[vee]

Your specialist doesn't sound too competent.
Does he have the relevant diagnostic equipment ?

Likely to be faulty oxygen sensors or lamda probes. At worst, a new cat ?