My Pilot has a Check Engine Light on and will display a code of P2279 when checked. I have already changed the intake manifold gaskets and the injector base gaskets but it hasn't worked. I have taken the car to two different mechanics and neither can locate any leaks in the system. What should I do next?

SOURCE: ENGINE LIGHT ON SLIGHT LOSS OF POWER AND POSSIBLE RATTLE

p2004 (Intake Manifold Runner Control Stuck Open)You need to take a look at the IMRC actuators on the intake manifold. You can try using a screwdriver or other tool to move the actuators to see if one is stuck in the open position. Do not use your fingers to do this, because if one is open and decides to close it has a bit of force behind it and can injure you. If the IMRC is stuck open, it is usually due to deposits in the intake manifold. Repair involves removing the upper intake manifold and cleaning out any deposits in the IMRC plate area. I would try running some Techron Concentrate in 2 tanks of gas to see if it dissolves enough of the gunk on the plates to free up the stuck one. Certainly a lot cheaper than having to pull the intake manifold and cleaning the plates. Always run tier one gasoline like Shell or Chevron to reduce the buidup of deposits.

SOURCE: my 97 honda civic dx check engine light keeps coming on

Had this issue did you replace the exhaust

SOURCE: Check engine light came on. Code P1456.

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.

SOURCE: 03 Honda Pilot Check Engine Light

yes reset by removing fuse or disconnecting battery make sure you have radio code if disconnecting battery. Problem may be oxy sensor in exhaust.

SOURCE: @004 Pilot the check engine

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.