what yr is this car.why do you think that removing the cat will make it run cooler?if you have an issue with cooling do you still have the small radiator with the oil cooler alongside or have you fitted the fullwidth radiator that came in the us version 380 & 500 sels?if the pipe work is done right with a double pipe cat[2inch in+2 and 2+2 out] you will have so little back pressure at 2000rpm that you will have trouble measuring it.call if you need more help.david poole european performance dallas tx.214-9567007.