We study the statistical properties of highly ionized absorbers using cosmological simulations. For each simulation, by considering a wide range of ultraviolet background (UVB), we show the statistical properties such as distribution functions of column density (N), b-parameter and velocity spread, the relationship between N and b-parameter, and the fraction of Ly α absorbers showing detectable metal lines as a function of N(H I) are influenced by the UVB used. This is because UVB changes the range in density, temperature, and metallicity of gas contributing to a given absorption line. The difference in some of the predicted distributions between different simulations is similar to the one obtained by varying the UVB for a given simulation. Most of the observed properties of O VI absorbers are roughly matched by simulations incorporating WIND+AGN feedback when using the softer UVB. However, this simulation fails to produce observed distributions of C IV and fraction of H I absorbers with detectable metals. We find redshift clustering can provide a good discriminator between effects of feedback and UVB as they affect clustering amplitudes at different length scales. We find in the case of aligned absorbers the derived temperature is mainly related to the optical depth weighted temperature from the region contributing to the absorption. The derived turbulent velocity dispersion probes the variance in the physical quantities across the region contributing to the absorption.