We study the core shift effect in the parsec scale jet of the blazar 3C 454.3 using the 4.8 GHz - 36.8 GHz radio light curves obtained from three decades of continuous monitoring. From a piecewise Gaussian fit to each flare, time lags \(\Delta t\) between the observation frequencies \(\nu\) and spectral indices \(\alpha\) based on peak amplitudes \(A\) are determined. From the fit \(\Delta t \propto \nu^{1/k_r}\), \(k_r = 1.10 \pm 0.18\) indicating equipartition between the magnetic field energy density and the particle energy density. From the fit \(A \propto \nu^\alpha\), \(\alpha\) is in the range \(-0.24\) to \(1.52\). A mean magnetic field strength at 1 pc, \(B_1 = 0.5 \pm 0.2\) G, and at the core, \(B_{\rm core} = 46 \pm 16\) mG, are inferred, consistent with previous estimates. The measure of core position offset is \(\Omega_{r\nu} = 6.4 \pm 2.8\) pc GHz\(^{1/k_r}\) when averaged over all frequency pairs. Based on the statistical trend shown by the measured core radius \(r_{\rm core}\) as a function of \(\nu\), we infer that the synchrotron opacity model may not be valid for all cases. A Fourier periodogram analysis yields power law slopes in the range \(-1.6\) to \(-3.5\) describing the power spectral density shape and gives bend timescales in the range \(0.52 - 0.66~\)yr. This result, and both positive and negative \(\alpha\), indicate that the flares originate from multiple shocks in a small region. Important objectives met in our study include: the demonstration of the computational efficiency and statistical basis of the piecewise Gaussian fit; consistency with previously reported results; evidence for the core shift dependence on observation frequency and its utility in jet diagnostics in the region close to the resolving limit of very long baseline interferometry observations.