Engine Management Sensor?

[Celeste16V]

My Clio is idling faster than usual, at about 1500rpm, and has a brief power loss at 3000rpm when accelerating.

The mechanic told me that the Engine Management Sensor (as he called it) was getting covered in oil, causing the problem. Is this plausible? What can one do about it, and where is this sensor?

 

[edde]

there a lot of secone be interesting to know which one he thinks it is.

I'c check the spark plugs firstly then check there no air gaps in the manifold.