A downhole PVT tool for performing in-situ formation fluid phase behavior characterizations in a wellbore using pressure, volume, and temperature (PVT) measurements of the formation fluid while continuing to pump the formation fluids. The disclosed downhole PVT tool includes an intake mandrel and utilizes two individual pumps to split the formation fluid to perform PVT measurements during the fluid pump out. The downhole PVT tool, two-pump configuration permits a first pump to be used to pump formation fluid along a first flowpath and a second pump to be used to pump formation fluid along a second flowpath, with one or more sensors deployed along one of the flowpaths to perform fluid and/or gas phase behavior measurements to determine one or more properties of the formation fluid in-situ. The first pump may be utilized in the phase behavior analysis while the second pump simultaneously continues flow-through pumping of the formation fluid.