The dealer read the service engine codes and replaced both the crank and cam position sensors. I found a chewed off vacuum line and replaced that but the engine light still comes on indicating the crank and cam position sensors. Could they both be defective? The spark plugs and wires have also been replaced. What else could be causing this. I read something about cleaning the top end with Seafoam but the web link to the procedure didn't work.

Were the DTC's cleared after the work was performed? If so, you could have other problems like fuel injectors, low fuel pressure, clogged cat, loose/corroded pins on the ICM terminal, or one of the coil/plug wire terminals not completely snug.