Doing a quick search on line on your code shows that its an evap problem this system deals with fume leakage it pumps air in to create pressure to check for pressure dropping ie aleak in the system. The reed valve switchs to signal the ecm from what i can gather this may lead to a limp mode of sorts its worth a quick search but it would also explain that clearing the code would allow the ecm to work properly hence no fueling issue.
