1.5TSI P2564 code intermittent

Hi All, I’ve recently had error code P2564 come up on my car (2019 octy estate 1.5tsi) however it is bizarre behaviour as it sometimes throw the code and puts the car into limp mode with an EPC light and Engine light on and a redline of of 4k and terrible performance. I can’t seem too find a pattern with the light coming on and off and sometimes it clears after a engine restart and doesn’t come back on for 1-30 miles- and other times after a restart it comes right back on. 
 

It does have a RaceChip tuning box, but it still has issues with the ‘dummy’ (pass through) box installed instead, so it seems not to be the fault of this. 
 

around 1000 miles before the issues started I did install a Forge air intake system- so this might be this issue. 
 

if you’ve had this issue and sorted it, or any thoughts on how I go about solving it do say! Thank you.