EML on my Corsa came on 4 years ago. My Indy mechanic said to ignore it as it would still pass the MOT. In May 2019 I had to get it fixed to comply with new MOT requirements. Mechanic put it on the scanner and replaced the 02 sensor. 2 days later it failed the MOT when the EML came on way to test centre (N Ireland). Same mechanic replaced another sensor for £95. Car passed MOT. EML came on again 2 months later.

Last November, I replaced the battery in both key fobs as they were the original batteries and the keys needed several presses to lock and unlock - EML has been off ever since!! A £3 fix!