CEL On P0300,P0301,P0305

[eyemann]

2005 EX 6 has CEL on and the codes p0300, P0301, P0305 which I understand refer to misfiring in the cylinder in the last number. Car has slight jerking sensation does not register on RPM but almost a nauseating feeling. Had this problem on my previous Nissan Maxima and traced it to the wrong spark plugs. Any other thoughts? The four fixes suggested by AutoZone were Plugs & wires. Vacuum leak? Injector fault? High or low fuel pressure? I have 63000 miles w/original plugs. Thanks for your help.

[Accordlover]

Are you over 36k miles/3yrs?

[stevel]

Originally Posted by Accordlover

Are you over 36k miles/3yrs?

his post says 63000 miles.

[2POINTautO]

Yes, complete tune up is next step to attempt to cure your random misfire.

[turBeau]

There suppose to have Iridium plugs from the factory that are good for 100k, but I just don't know if plugs can last that long. Just get some good ol' NGK V Power's for a couple bucks each, gap them properly, and change them every 30k. Copper is the best conductor.

You don't have plug wires, so I hope a coil isn't going south. Do the plugs and get back to us.

[princess]

take a peek:


http://www.driveaccord.net/forums/showthread.php?t=8850

[TonyWare]

princess, what eyemann describes and the bulletin you posted are a match. However I wonder if eyemann has been doing his regular services at a Honda dealership where that bulletin would have come up in their computer as a "silent recall" or "product update" for the ECU.

So, it may be a good idea for eyemann to first check with any Honda dealership (using his VIN) to see if that procedure has been done on his car already. Reason being that if it has been done then eyemann is probably looking at an EGR valve stuck wide open issue or some other leak from the tubes that go in and out of the manifold causing cylinder misfires.

[2POINTautO]

Just a tid bit of info for Iridiums, yes I am not sure if I would even let plugs go that long, no I would not BUT, Iridiums are stronger the platinums and if you know anything about spark, you are talking about copper is the best conductor, not if is is round like plugs get after just one years usage, spark needs to jump from a sharp edge to be good and strong.

Remember the old days of fileing the tip of the plug and then regapping to the correct gap, that was to make the tip flat and have a sharp edge to it. Iridiums have a very fine tip and will almost resemble a sharp tip over many miles and years, its hard so it wont burn away as easily and that very fine tip is much more difficult to carbon over during a very rich condition so they tend to still fire when most plugs will be too rich to work and just short out completely.

My two cents on Iridiums, I might change them every four years, 50K@.

[eyemann]

I pulled the number one plug just to see what was installed in my V6 2005 Ex amd tjhey were Denso's. I checked gap and it was way off so I gapped it to .044 and screwed it back in. Ordered a new set of NGK's on ebay and three days late my CEL was off? Could this have been the problem? I am still going to change the plugs per the suggestions. Thanks for the help. New to this forum as my 93 Maxima with 210000 miles finally quit. Their web sit was similiar to this and also very helpful. All models have the same problems.