Recently my car's check engine light turned on, ever since then every time I attempt to turn on the car it has difficulty turning over. Here are the Codes: P0300 P0301 P0302 P0303 P0304 P0305 P0306 P1456 I attempted to search Google on the meaning of these codes and i get mixed messages. If someone can clarify what might be the problem that would be greatly appreciated. 2000 Honda Accord LX V6

  • I can add this as an answer if it works out, but I would check the EVAP purge valve. You can test it by removing it and blowing through it. If you can blow through it even a little bit it's bad.
    – user288719
    Commented Jul 5, 2016 at 15:28
  • @user288719 much appreciated, if you don't mind could you let me know where I can locate that. I'm searching yet can't find anything specific that matches my cars make and model. Thank you very much again.
    – user19555
    Commented Jul 5, 2016 at 15:34

2 Answers 2


Since I can't add images in a comment I had to add as an answer. Apparently Honda called the valve in question a two way valve.

enter image description here

  • Although you can link to pictures in comments...
    – Cullub
    Commented Jul 5, 2016 at 16:36
  • The two way valve is not the purge solenoid. The purge solenoid is located in the engine compartment.
    – Ben
    Commented Jul 5, 2016 at 20:56
  • That's what I thought, but there is no mention of it on the parts breakdown. Not sure if I have an incomplete revision or what.
    – user288719
    Commented Jul 5, 2016 at 21:37

P1456 -small evap leak detected. Very common problem on Honda. I appears to be the O ring on the filler pipe assembly.


Code P0300 - Causes and Fixes

Code P0300 is a code that is generated when your engine has a misfire that is not related to only one cylinder.

Sometimes this code will be set in addition to other codes such as P0301 which means that there is a misfire on cylinder 1 (cylinder 1 is the number one cylinder when looking at the firing order. It is generally the forward most cylinder on the engine.). If these engine codes are present as well the you should diagnose those first as they are probably causing this trouble code.

This code will set your check engine light and needs to be fixed as soon as possible. If it is not then you will probably need to replace your catalytic converter as well as the problem that is causing your misfire.

There are many causes for this OBD code. Since it is a "random misfire" or "multiple misfire" this means that the misfire is on different cylinders and not just one all the time. What Causes a P0300 Code?

Low Fuel Pressure
Vacuum Leak
EGR system malfunction
Internal Engine Problems (such as low compression)

Less Common Causes

Faulty Coil
Faulty Spark Plugs and/or Wires
Camshaft or Crankshaft sensors
Ignition module

To troubleshoot, repair and maintain your vehicle, you'll need diagnostic and repair information that is specific to your car or truck.


  • If it's the O ring why would that cause such a harsh turn over. The engine has a hard time. Really curious....
    – user19555
    Commented Jul 5, 2016 at 19:30
  • The hard turnover could be another issue not addressed in the codes.
    – Old_Fossil
    Commented Jul 5, 2016 at 19:40
  • Any idea what it might be? Cause literally when the CEL came on was when the turn started failing.
    – user19555
    Commented Jul 5, 2016 at 19:42
  • By hard turnover: Is it referring to the the engine itself not turning over i.e cranking ? Or Is it referring to the engine not starting ie ignition related?
    – Old_Fossil
    Commented Jul 5, 2016 at 19:47
  • Yes, absolutely correct.
    – user19555
    Commented Jul 5, 2016 at 19:48

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