The C-12 (O-18,O-16)C-14 and C-13(O-18,O-17)C-14 reactions were studied at INFN-LNS laboratory in Catania. The experiments were performed using an O-18 Tandem beam at 84 MeV incident energy. Charged ejectiles produced in the reactions were momentum analyzed and identified by the MAGNEX spectrometer. Q-value spectra were extracted with a remarkable energy resolution (FWHM similar to keV) and several known bound and resonant states were identified. In particular, states with relevant 1p-3h configuration with respect to the 180 core are mainly populated by the reaction (O-18,O-17) while states with known 2p-4h configuration are excited by the (O-18,O-16) one. Exact Finite Range Coupled Reaction Channel calculations based on a parameter free double-folding optical potential were performed to reproduce the measured absolute cross-section angular distributions. The (O-18,O-16) is found to be an important probe to study pair configurations in nuclear states.