EGR code 16 simply means the EGR system is not working. You want to check the SOV and vac line feeding the EGR . If that has no vac , you will have no egr valve actuation.
The EGR test you mention is egr flow test by you manually open/closing EGR..if that attempts to stall engine, you know the valve and passage to the intake are OK, but you do not know if you have vac/sig to operate the valve b/c your manual test by-passes those inputs of the system..

Do you have the 16 or 8 pin diagnostic connector box??