I have a 2009 Toyota Matrix 1.8L that recently needed a head gasket replaced. I replaced the gasket and the car ran fine for a few day then I started getting a Evap. Improper Purge code. I re-examined my work and sure enough I had broken the two wires going to the purge valve. They looked to be twisted and shorted together. I repaired the wiring and went on my way. Now I'm getting Lean Bank One code and Large Leak Evap. System code. The purge valve is good. I checked it by cranking the car and running 12v straight to the valve. It opens and closes correctly. The problem is that the valve stays open all the time because it is constantly getting 12v and ground.....so now I have a vacuum leak. 

My question is whether the purge valve is controlled by a relay that that may be stuck in the on position or is it controlled directly from the ECM. I reset the ECM by removing the negative and shorting the leads so as to drain all the current from the caps. That didn't help. 

Is my ECM damaged? Thanks for your time, 

Fish-Stick