Late 1985 calif only and 86-87 I think. It is easy to tell..Of the three 300SDL's I looked at before buying, only one had it. Look on the pass side of the engine, next to the valve cover. If there is a big ugly thing that looks like a motorcycle muffler, the trap is still there..If it has a piece of pipe bolted in with some shiny heat tape on the top, it has been replaced.