Small update.
Will still be going to Snetterton in the morning for trackday. At least I can see how new wheels and tyres perform. (Forecast is good)
Will leave at lunch interval though as ive managed to get a local garage to fit me in for the afternoon. Having new spark plugs and a new camshaft sensor fitted in an attempt to tick off some less costly reasons as to why the car is underperforming.
Also have my eye on a catalytic converter on eBay off a newish 200 that I hope will fit!
If all of these don't remedy the situation then I will have to bite the bullet and give the car back to Andy at Engine Dynamics and ask him to sort it
Thanks for looking