Well after the bit of trouble I had after fitting the exhaust, the car is running fine now. But holy moly it has absolutely destroyed my mpg. It has literally halved it and for not much of a gain in power, it has me thinking is it really worth it. I mean when giving it the beans my mpg goes down to 3mpg where as before I put it on it never dropped below 12. While cruising I am only managing at most 30mpg compared to 45+ before.
So I am no contemplating going back to the standard unit. Has this happened to everyone who has changed up.