# P1456 code for SERVICE ENGINE SOON



## schow08 (Nov 28, 2008)

My 2003 Pathfinder LE has 44400 miles in it recently the ServiceEngine light was turned on and I have tried to properly secure the fuel cap and filled the fuel tank,despite that the SERVICE ENGINE SOON LIGHT was sitll on.
Subsequenlty I took the car to a local Auto Part store the Engine code is P1456.
Few days later the light turned off but again about 4 days ago while I was driving on a rough road with fuel indicator showing more then half is full the SERVICE ENGINE SOON light again turned on and now it is the same CODE P1456.
What I need to do now regarding the emission system?
Change the fuel cap or other option?
I would highly appreciate input in this regard.
Thanks.


----------



## Quick69GTO (Jun 8, 2008)

Could be one of the following (if equipped):
Fuel filler cap, vacuum connection, fuel tank, fuel tank pressure sensor, evaporative bypass solenoid, evaporative two way valve, evaporative control canister vent shut valve, evaporative control canister and evaporative purge control solenoid. 
The code just refers to the fuel system not being able to contain/dispose fuel vapor according to the ECUs programming.
Because of the complexity of the system, it may take a couple of hours and some specialized equipment to diagnose the cause.
Some of the components listed can be pricey, so be sure the right one is replaced.
You may get lucky by replacing just the gas cap.

Good luck!


----------



## schow08 (Nov 28, 2008)

Thanks for your kind advice.
Yesterday I have cleaned twicethe fuel cap and the edges of the fuel tank where the cap fits,and surprisingly this evening the SERVICE ENGINE SOON light has spontaneoulsy turned off.


----------



## GimmieSumMo72 (Nov 27, 2008)

throw some dry gas in your tank... should help with the vapor issue.


----------



## tom lang (Jan 20, 2017)

Can a P1456 DTC (2003 Frontier, 4cylinder) also cause a misfire code (e.g., P0302)? I have both, and at one point did the fuel cap trick and cleared the SES lamp. It's now back.


----------

