Date Added: Saturday 23 November, 2013
Yey it's fixed!
Having read forum after forum, it turns out this little bad boy has been a very bad boy indeed!
Poor idle, cutting out, poor running when warm/hot, spluttering and coughing? Change this sensor first. Be sure to replace genuine only.
Remove the coil pack, remove the metal spring clip from the green sensor connector, take a 18ml spanner/socket to the sensor and replace. Difficulty - 3/10 I'd say (and I ain't a mechanic!)
Also a big thanks to MX5 parts for their great service.
Hope this helps :)
Rating: [5 of 5 Stars!]