hiya. yesterday my car was holding boost at 1bar fine afta 2 weeks of probs. well 2day iv took the air box off it again n put this air cone back on. n now it trying 2 boost at bar again.!!
im gona have 2 put the box back on it but y is it doin this?
do i need a 3 bar map sensor n ecu tune 4 an air cone?
thanx

 

The filter should make little difference to boost!

I've had -

Cone
Escos airbox
RS500 airbox

None of them have changed the boost pressure lol

You haven't disturbed any of the actuator air lines have you?

 

As above, perhaps you banged something/knocked something off when taking out the airbox. Maybe check the AMAL valve connections for pipes and wiring.

Good luck