At one point they discussed jettisoning the landing stage of the LM, for less mass so that the PC+2 burn would get them home faster, but most of the batteries and O2 tanks on the LM were in the descent stage (4 of the 6 batteries, I don't remember the distribution of the tanks) so dropping the landing stage made their other problems even worse. The landing stage stayed attached to the ascent stage for the entire life of Odyssey, and was dumped into a deep trench in the Pacific Ocean because there was a nuclear RTG to power the ALSEP attached to one of the legs of the lander.