IMTV question

[EVI]

Could someone please explain to me what the IMTV is and how the IMTV open and IMTV closed are different.

[GMPX]

EVI, this is explained in the software in the description for parameter - B8206
"Determines if the engine is fitted with a Intake Manifold Tuning Valve (IMTV) used to vary intake runner length.
If no valve is fitted, all 'IMTV Closed' VE Terms can be ignored.
The IMTV status can be logged in the Scantool using the PID 'GM.IMTVSTATE2'."

If the parameter is set to No then ingore anything to do with IMTV states.

Cheers,
Ross