Oldsmobile Questions? Ask a Mechanic for Answers ASAP
your evap purge valve is sticking open this will cause both codes and i guarantee that is your issue.
oh sorry i misread the 440, that would be a broken evap line between the purge valve and tank
the lean code gets caused by sucking air, likely the purge valve pulling fresh air, and the non purge code shows the purge valve cannot put vacuum to the tank, so there is likely a large leak in the system or a split line, follow the line from the purge valve back and look for damage, if you cannot find any it may need to be charged with smoke to find the leak.