I agree, the Redex was a more play it safe type of thing only put 20ml in to 10 litres didnt really want it in my tank anyway. Also quite tappy, think its my valves as there not hydraulic so didn't want to possibly ruin any seals with the Redex.
UPDATE:
Still not sure on what caused the readings but as I had a faulty lambda for months (making me run rich) I cleaned my spark plugs, which were pretty sooty. Ran some Redex and red lined my way to the garage. Passed with ease.
Also believe that it could have possibly has something to do...
I had the management light on for a good 6 months, literally changed the sensor just as I went to test and cleared the codes. I assumed it would need running in for a few miles. Im going to disconnect the battery to reset the ECU
Make: Ford
Model: Fiesta Zetec
Engine size/Type: 1.4
Year: 2004
Mileage: 86K
OK so MOT failed due to CO emissions during natural idle but appeared to be fine during fast idle. Any help appreciated at this time need to get back on the road ASAP and cannot figure out what could cause this...