I just bought a 2004 Mazda 3i Sedan with 83k miles from a local dealer. When I took it for a test drive I noticed that the engine light was on. I asked them to take care of it before I purchased. They said it was some kind of salvenoid valve? I think I am spelling it correctly. Anyway they replaced the valve with a new one and the engine light was off. After I picked up the car, it was about 60 miles of driving and the light came back on. I went to Auto Zone and the codes were P2187 and P0455. The guy there said something about an EVAP EMissions leak and a System lean? Anyway, if someone could help that would be great. My brother-in-law is an ex-mechanic so if someone could let me know what parts I need, I believe he would be able to put them in for me.(Hopefully it is that simple)

Thanks.