Ranger Mods

Noticed my Ultragauge will read negative boost (vacum) value when off the throttle every now then. Its like the 'zero' shifts a couple of psi back. Stop, restart and all is good. Am i not understanding something or.......?
PX3 xlt auto

Will be to do with EGR.

Block EGR and you will see vacuum on throttle off everytime. Unless you are seeing a high figure vacuum then I would say everything is working as it should.

Generally no more than -5psi ish.. So this is normal then? Not real keen on doing significant mods yet - only 4mths/ 8000klm new

Mine does that while it's doing a burn..

Being EGR is closed from memory when a burn takes place it would make sense.

have seen this. Also cmd throttle position position 50-60% during a burn and reduced boost pressure when driving. Assume it is to reduce airflow thus causing rich mixture to increase ext temps for regen

Did this get confirmed as occuring during a burn? I've started to have a similar issue at the same time as my VGT actuator failing. Has happened 3 times in last ~800-1000km where if I take my foot off the accelerator, boost will drop to -3 to -6psi and engine revs will bounce around, drives really rough.

I've set up the scangauge to monitor boost, soot %, EGR position and EGT13. Will monitor to see when it happens next, but I've also just gone into COVID iso