Well I picked it up yesterday and the cambelt fault has now been rectified by looks of it as have done about 50miles today with no problems..

The P1518 fault however still persists and the car is not as punchy as it was before. I'd guess its running ta say 75-80% the power it was before.

Ive never done it before but Im going to have a look at digging out the IRMC and seeing if I can do anything with it. I dont really understand what the IRMC even is and how it works but have seen theres quite a few threads and vids that suggest it may be something i can fix myself. The fault was explained to me to be like a butterfly valve that opens and closes and the fault code suggests its stuck open.

Would it be right to say therefore that the problem could either be the IMRC (the little control box thingy) not working properly or the 'butterfly valve' itself being stuck open? If so where is this butterfly in relation to the IMRC unit? The garage told me the cable itself seemed to all look in working order if that helps. ????