I just bought a 2000 Honda civic ex for my step son Friday evening. I checked it out and it ran fine as I test drove it. On my way home the check engine light went on, jerking was felt as i decelerated, and my idle was jumping up and down while at a complete stop... Sometimes low enough to where i thought It was going to stall out. I took the car to Autozone to have the code read. It threw a P0505 and a P0420. Im planning on taking it into a mechanic tomorrow morning and dont want to get bent over. Any Ideas on what Im looking at having repaired? Thank you

 

just going out on a limb here, but how the heck would you consider the "classic honda pre-1988" section the appropriate place to ask this question.