If you know that the changeover valve is broken then you need to replace it. As for the fault, check for a broken vacuum hose, or leak and if so repair and retest . If vacuum hoses are fine and no vacuum leaks check to see if your combi valve is bad and leaking, it is very easy to tell there will be a loud hissing noise under the intake manifold when the engine is running. if that is ok check the mass air flow sensor, and the oxygen sensors.
replacing the fittings
Yes.
By replacing the whole gasket.
A Pachner move is any of a set of ways of replacing a triangulation of a piecewise linear manifold by a different triangulation of a homoeomorphic manifold.
do i need to change the manifold when replacing thermostat
i am replacing the starter on olds 1995 aurora
Cracked intake manifold...
A bistellar flip is another term for a Pachner move, any of a set of ways of replacing a triangulation of a piecewise linear manifold by a different triangulation of a homeomorphic manifold.
About 450.00
Intake manifold or exhaust? The complete job (parts and labor) is between $700-$900. depending on labor rates.
It's supposed to do that.
Absolutely not. The two are not related in any way. If this was just a personal concern, just replace the intake manifold gasket. If this was what a repair station has quoted or already charged you for, Id go somewhere else or talk to a lawyer respectively.