turns off when i don't press the gas,at red lights etc etc....the service engine soon light comes on and the battery light...anybody have any idea before i go to the mech and he tells me i need 1000 things and i really only need one..

 

What code is it giving? You really need that to properly diagnose the situation.

With that being said, my improper diagnosis (wild guess) would be the battery and/or alternator.

 

Go to AutoZone and ask them to check the trouble codes. They should do it for free.

 

not sure about 5th gens but i kno alternator for nissans is usually brake light + battery light

 

check MAF man.

 

i just had the same problem on my 00 max, it was a bad senser just under the TB intake, forgot whats it called, but i replaced it and it runs perfect.