Ok i need to pass the emisions test to get new stickers on the max by the end of march and i went to get the test done and the SES light was on. They automatically failed me and told me to go have it checked out. I went and checked it out it points off to be P0400. I looked it up here in the stickies and with some help from Kevlo911 i managed to get a better understanding of what can be wrong. I tried to take the EGR Valve off and I cant seem to get the big vacum line off. ANy input on how to take this valve off would be apreciated. THanks guys.

 

EGR valve is hardly ever the culprit...most likely EGR solenoid valve,,check this for help:

How to troubleshoot EGR problems.
http://img52.photobucket.com/albums/v158/evilBIGD/EGR/

also check this thread:
http://forums.maxima.org/showthread.php?t=357902