Hi, can you give some more info.....what's your mileage, any other symptoms, noises, preculiarities that may be linked? You say you've had a new sensor fitted, by someone else? If someone else/ garage, did they run any other tests and checks, oil and oil pressure etc, to satisfy themselves it was just the sensor needed? Are you happy that your oil isn't too old and or too low? Has it been using a lot of oil with no obvious external leaks.....when you say it keeps coming on after start up, are you saying that it comes on and stays on, or does it come on randomly during a journey. Are there any particular times that it comes on more often that not, for example, sharp turns, under quick acceleration, sharp breaking etc.