Thought i was right and that id seen the info somewhere before......www.rsbible.co.uk

"You should have a suppressor with your OFAB MAP sensor.
If you do not have this connected, you run the risk of damaging either/or the MAP sensor or ECU. It will also feed the ECU incorrect information, causing running problems, and/or damage to the engine. It may seem however that the engine is running with no problems.
It's worth noting, that these supressors are no longer available from Ford, and when they were available, they were £100 odd!
However, if you need one, speak to Kenny at http://www.motorsport-developments.co.uk/ He will be able to supply you one new for £50, delivered."