Hi Luke,

Can you post the 4 gas emissions at idle and fast idle. This may give an indication of what is happening to the fuelling and point you in the right diagnostic route. LTFT would also be of interest.

Kev is right about the carb cleaner not being a good test. A good healthy squirt of Easy Start does the job for me . Finds an air leak from a hundred yards!

My hunch is a faulty MAF. Can you try disconnecting it and see if there is any improvement in the running of the vehicle?

Regards

Pete M