Ok guys my wifes car thru a few codes today it is a 2003 Nissan Altima 2.5S with a standard shift transmission. they are as follows P0507, P1546, P1456. Ive seen a couple of these and got the ECM reset and everything was good until recently. Any help is greatly appreciated!

P0507 idle air control system higher than expected. P1546 A/C clutch status circuit low voltage. P1456 leak detected in fuel EVAP system.

"P1456-- leak detected in fuel EVAP system." Check the gas cap!! first.

Thank you for the help.

What is your idle like, to high or to low?

It seems to be pretty normal.

The code p0507 idle air control system, idle higher than expected. Causes: Electric throttle control actuator, intake air leak, pcv system. If the code comes back try disconnecting both battery cables and touching them together for 10 seconds.This will reset all the self learned settings. Cycling key on for one sec and off for 10 sec three times. This may reset the idle air volume learned by the pcu. The code p1456 leak detected in fuel EVAP system. Causes: Loose gas cap, poor seal in fuel EVAP purge valve, leak in fuel vapor hose. This code can be a pain, start with the gas cap. If ok vacuum test the purge valve, must hold vacuum on both sides. EVAP line needs to be inspected for cracks or loose fittings from the fuel tank to the canister, from the canister to the purge valve,and from the purge valve to the intake manifold.

Well thank u sir! I will have to now find the evap can so that I can pull a vacuum on it. Thank u for all the help sir!!!

You want to vacuum test the purge valve, not the canister. The canister is a place where the vapor is stored. The vapor is later sucked in to the intake manifold when the purge valve gets a signal to open.