A couple of months ago the check engine light came on. The codes were P0300,
304, 305 and 306. I used fuel injection cleaner with two tanks of gas. Subsequently the check engine light went out and has not come back on for weeks. It is still not on, but the codes remain. Do I still have the problem indicated by the codes?John
2002 Dakota 3.9, QC, auto and for the REDNECKFROMHELL it is Pat. Blue
No - if the condition isn't active, the check engine light won't illuminate, but the codes are still stored for diagnostic purposes. They will eventually clear on their own, after a certain number of ignition cycles - but if the CE light isn't on, you don't need to worry about it.
The light going out usually indicates that the PCM no longer sees an active problem but the codes will be retained for a period of time to aid in diagnostics should the problem be of an of an intermittent nature. You can clear the codes by disconnecting the battery for about 5 minutes or if you have access to a code reader with that capability and if they do not return. problem solved.
Thanks Tom L. and TBone
John
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