Mk1 Focus Failed MOT on emission

[Captain Answer]

My focus has failed the MOT on emissions, results as below. It has had new plugs, leads and I've put redex through the system in the last few weeks. I fault code read the ECU but no codes were found, garage recommended the Lamda sensor, so I've ordered one for retest and put in a new air filter.

I noticed on the air intake one of the screws is missing, this was not the case last year, it looks like it has been cutaway at the last service, so I will try and find a bolt to go through there also before the test.

MK1 focus, 122k on the clock driven fairly hard and usually clock 150 miles a week. Oil, oil filter, plugs, air filter all changed last summer.

Any other recommendations would be fantastic

First fast idle: 2750-3150 rpm (sheet states engine speed: not checked)

CO (<0.3%) result 0.46% - FAIL
HC (<200ppm) result 52ppm - PASS
Lambda (0.950-1.090) result 1.007 - PASS

Second fast idle: 2750-3150 rpm (sheet states engine speed: not checked)

CO (<0.3%) result 0.39% - FAIL
HC (<200ppm) result 29ppm - PASS
Lambda (0.950-1.090) result 1.004 - PASS

Natural idle test - PASS
CO: (< 0.5%) result 0.5%

Edited by Captain Answer on Thursday 16th May 20:39

Edited by Captain Answer on Thursday 16th May 20:40