Check engine light came on... Code given is 05-03. I've checked the gas cap, turned the engine switch to on and off 3 times and nothing seems to clear it. Help!

What code ? P0442 or P0456 or p0455
DTC EVAP P0442 P0455 P0456
EVAP Leaks P0442 and P0455

Wells EVAP Training with Sgt Tech P0440 P0441 P0442 etc

If the gas cap is tight then rpelace it.

code P1456 set when there's small leak in the fuel tank system.
Most known reason for P1456:
-Didn't tight fuel cap on until it click for more that 3 time after fueling up and drove the car too long with cap loose.
-or a bad gas cap.
I'll try tighting the gas cap.
clear check engine.
if code come back, replace gas cap and clear check engine light again.

When you remove the cap it set an evap code nothing to worry about. take it to a garage and have the code removed.

2004 Honda Pilot engine light came on this morning. Last bought gas 5 days ago. Auto Zone checked and found code P1456, emission control system leak detected (fuel tank system)
Four options;
1) Loose fuel cap
2) Vapor canister saturated
3) Failed vent solanoid
4) Failed purge solenoid

Thanks.

The purpose of the check engine light is to inform the driver that the car's ECM has registered a problem. It then stores a code in it's memory that can then be "pulled" by a hand held diagnostic trouble code reader and usually the issue an be corrected. More times than not, the car will seem to be running fine even with the light on because the ECM will compensate for the problem as much as it can to keep the system functioning. One thing you can do is remove the gas cap and put it back on making sure that you securely tighten it until you hear 3 clicks. After driving the car for 30-50 miles, the light may go out. If it does then the gas cap was not tightened completely causing air to enter the system (the system utilizes vacuum so it must be sealed air tight). If the light stays on, take it to a Dealer or trusted mechanic for further inspection. ALWAYS BE SURE YOUR GAS CAP IS TIGHTLY SECURED AFTER EVERY FILL UP OR THE LIGHT WILL COME ON AGAIN>

Did you change the gas cap with a Honda gas cap? Tighten it at least three clicks?
Also, Honda recommends that you never top off the tank when getting gas (only go to the click-off of the pump; otherwise you can get back flow into the system that will cause the code).
Tightening or replacing the cap will not immediately cause the light to go off; it can take up to three days of driving for the light to reset.
To check if your readiness codes (emission system) are set, turn the ignition to ON (II), without starting the engine. The Malfunction Indicator Lamp will come on for 20 seconds. If it then goes off, the readiness codes are set. If it blinks 5 times, the readiness codes are not set.
You can, of course, try resetting your engine light to see if it will come back on (which it probably will). I believe the procedure is:
Turn off the engine.
Press and hold the Select/Reset knob (odometer) in the instrument panel, then turn the ignition switch to ON (II).
Hold the knob for approximately ten seconds until the indicator resets.

Hope this helps you.

If you have an Advance Auto Parts store where ever you are, they will read the code and tell you exactly what to code is and what it means. Any mechanic who "guesses" isn't a mechanic at all - he's a thief. Emissions leak can be any number of things, but not the gas cap!

This could be a number of things causing this ...most common is that after you fill up the gas cap is not fully tightened...make sure it "clicks" 3 times while turning.The other common problem is that the gasket on the gas cap is old and thus does not seal the tank/fuel filler area...check with replacing the cap.If neither correct then you will need to bring to a service center or dealer to run a code check...maybe a bad O2 sensor or a code for the transmission.

change the gas cap the tank has a perssure switch that is throwing the code