djalbin
Senior Member
Join Date: Dec 2014Location: Tucson, AZPosts: 1,478
Quote

oes a tuner just turn off MDS, or does it also delete the diagnostic tests that sense the MDS Solenoids?
The onboard diagnostics only check the MDS system when MDS is either transitioning from 4 to 8 cylinders or transitioning from 8 to 4 cylinders. If MDS is disabled the MDS system never transitions from 8 cylinders and the diagnostics are never executed.