The haynes manual doesn't cover the ST200 specificaly and nowhere in the index does it mention the Knock sensor or the MAP sensor, so I have no idea where to look. my local garage is useless... my sister knows more about cars and she's a hair stylist!

Does anyone know if a session on a rolling road would be a better option? The car will be 'under load' so to speak and therefore the operator would be able to see first hand what the problem feels like while driving?

Jimmyboy, if i get it sorted, the whole world will know! lol been driving me nuts!

But feel free to keep me informed of any progress you make and i'll do the same....

Cheers for the help guys,

Lee