UK 528 E39.
Car failed twice at one testing station for 'Natural Idle Test' CO
emissions, at 0.85%
Today the car went to my local BMW dealer for a diagnostic check.
No faults reported by the ECU. Exhaust system was examined and was OK, so
they checked the emissions as per an MOT. All emissions were well within
limits. Inc 'The Natural Idle Test', which was 0.50%. A big difference to
the fail figure.
As nothing was done to the car since it's last failure, I'm beginning to
wonder just how reliable the MOT computers are, or is it more likely to be
due to the examiner not getting the engine hot enough?.
How often are test station computers checked?