i just replaced the 02 sensors becouse i had an error code. and guess what the light turns on again (engine check light) know its telling me i have a p0440 and p0446 codes its somthing to the with the EVAP valve and circuit telling me that there is a malfunction. does this effect my prefomance and gas milage is there a way to fix it?

 

The 446 code does not affect the performance of your maxima. It is a diagnostic function only. I went back and jiggled and disconnected/reconnected the wire harnesses back by the evap cannister(behind driver side rear wheel) and the p0446 code disappeared.