We propose the use of soft feedback estimates for the PIC detector in a DS-CDMA system with FEC. The soft estimates are computed by the a posteriori of the log-MAP decoder. We compare this method with the conventional method of using tentative hard decisions to perform interference cancellation at each stage. Simulations under AWGN and multipath asynchronous channels are performed for comparison. We supply a suitable a posteriori for the log-MAP decoder, and obtain a suitable soft feedback from the decoder.