Change back box

Currently have a full decat system on with a Peco s/stl back box. If i was to change the back box to a P1 box which i like the noise off would i need a map as the car was mapped with the Peco one on ? Getting a bit tired of the drone off mine and the P1 box is far more subtle...........i would be leaving the centre and decat as is......Any thoughts ??

IF just a back box change I reckon you would be fine.

if you are increasing flow, ie putting a bigger exhaust on it becomes dangerious. Spiking etc...

i know lads that have changed full exhaust systems with no issues but thats helping the car to breath

my car was mapped for a 3" exhaust and when i put a 2 and a half inch exhaust on the car it would hesitate as it couldnt get the air flow out

you should be ok if its just the back box