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TLPMYD 10-18-2013 01:11 PM

300 & 304 codes
Had those codes 300 & 304 popping up so I replaced the plugs and I'm still getting the same codes, will it go away on its own or did I have to disconnect the battery to let the codes reset??

TLPMYD 10-19-2013 06:13 PM

Re: 300 & 304 codes
Anyone? Thanks in advance

Frango100 10-20-2013 10:33 AM

Re: 300 & 304 codes
Im not an expert on WK, but i believe that you have to reset the code using a scanner. If you have an Android phone, you could install the app Torque (the free version will do) and just buy a cheap bluetooth dongle for the wireless connection with the jeep and you can read fault codes and reset them yourself. It will also show many live data for eventual trouble shooting, very nice app.
If the fault is not there anymore, it should reset finally, but that will take many key cycles normally. Not sure from the WK how many.
Did the jeep run rough before you changed the plugs and did it change after the change?

TLPMYD 10-20-2013 10:44 AM

Re: 300 & 304 codes
J surely feel a change in how it rides, I pulled out autolite xp's and replaced them with NGK V-powers, seems to run smoother and sound quiter also, just the same two codes are appearing, and I'm overdue for inspection and not sure if they will automatically fail me for the check engine light on for only those two codes that still show up, and if I disconnect the battery so the light goes away ill have to drive it another 150 miles before I try going to inspection again or else they will just reject me

Frango100 10-20-2013 07:07 PM

Re: 300 & 304 codes
Not sure if the check engine light will go out by disconnecting the battery, but the codes will not errase from the PCM memory.

TLPMYD 10-20-2013 09:35 PM

Re: 300 & 304 codes
How long or many miles you think I have to drive for the light to go away?

TLPMYD 10-21-2013 07:00 PM

Re: 300 & 304 codes
Or would it be a better idea to just disconnect the battery so the light goes away and shouldn't pop up again since I replaced the plugs

Frango100 10-21-2013 08:29 PM

Re: 300 & 304 codes
It is normally not distance related, but more key cycles or cool down cycles. Better to take it to a shop to errase the PCM memory.

TLPMYD 10-21-2013 09:37 PM

Re: 300 & 304 codes
Good to know so then any idea how many cycles? Just curious thanks for all your help so far.

TLPMYD 10-27-2013 10:25 AM

Re: 300 & 304 codes
so here's where i stand today, disconnected the battery friday, the check engine light and codes went away and i thought thats all it needed until today, woke up this morning to take the jeep for a spin and ding, 300 & 304 are back, so i know its not the plugs since i put new ones in, and i made sure to switch all the coils to different spots, then disconnected the battery till check engine light and codes went away....till today and its still giving me 300 & 304 so what else could it be?

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