My check engine soon light has been on. I checked the ECU and have gotten 3 codes with the diagnostic tools provided on this site (they wouldn't check the codes at the dealer for free even though i've been going there since i purchased my Maxima so I figured I could do it myself, many thanks!).

0303 - Front Left Heated 02 sensor
0704 - Evap control system pressure sensor
0905 - Crankshaft position sensor (position)

I'd like to see if anyone has any suggestions as to what I might need to do before I take it into the dealer and possibly get ripped off.

Cheers!