Lexus Repair: check engine code po440, 2002 lexus rx300, lexus rx300

Question
On 11/24/06 I had the oil changed on my 2002 Lexus RX300 at a quick oil change place.On the night of 11/27/06 the check engine light came on.I took the car to the dealer the next morning.Invoice reads po440 vent control malfunction-repaired cannister control valve.service writer told me they repaired some wires & that the oil change place probably damaged them when they checked the air filter.I went back to the place that changed the oil & they said that they could not have damaged the wires.The light came on 600 miles after the oil change was completed.Could the oil changers have caused the damage.Thanks in advance.

Answer
Anything can happen. They may have, or anything else could have happened to it. Never go to such a place. People that work in places like that are f***ing morons. Not to mention in general they use the worst quality crap & replacements.

Take it back to Toyota, or Lexus. The emessions equipment is most likely still under warranty.