What's an egr valve?
 

my check engine light came on and i got a code 0514 wich didn't show as anything on the ecu decoder. on the haynes code it translated to a p1402 wich points to the egr valve. does anyone know what an egr valve is and where i can find out how to fix it. any help wouold be great. thanks

http://forums.maxima.org/showthread.php?t=104931 3rd link defines each code :D