What? My CEL went out on its own!!

[RickC]

2011 Ram 1500 5.7L 4wd 149,750

My CEL became ‘active’ about 15 months ago at around 145k, and as luck would have it, my scanner showed the P0303 misfire code. I immediately went into panic mode knowing this could be the cam/lifter fiasco the 5.7 Hemi is known for, but I also knew there may be other explanations for the CEL/code.
I purchased 8 used coils and played merry-go-round with them, always getting the same code, and sporadically, P0300 alongside P0303. I installed new plugs. I used FI cleaners and only the best fuel; for oil changes, the correct oil, hoping something ‘else’ May have triggered the code.
Nothing seemed to work—I would clear the code and it would always return at some later point.

I rarely use this truck so the issue was never a priority to fix; I also never pulled the valve cover to check the spring or rocker lift, so I just lived with it. I would clear the code now and then and drive the truck when I needed to. Simple.

But something odd just happened yesterday—the CEL that had been currently illuminated for over 2 weeks, decided to go out on its own! I got in to drive home and noticed it was gone!
I then scan the OBD and there’s nothing there—this has NEVER happened in almost 2 years.
How can this be?
Am I now supposed to suspect some OTHER issue?!

Rick

 

[JohnnyMac]

Russian collusion....

 

[drdarrin]

They say these things are smart enough to fix themselves... Welcome the rise of the machines!


Sent from my iPhone using Tapatalk

 

[Outbreak]

The bulb burnt out.

 

[RickC]

No Russian collusion—heard it on the (fake) news; has not become self-aware...yet; the bulb is DEFINITELY still good. Next!

 

[smithwessn]

In most instances, a CEL will go off on its own with 2 consecutive drive cycles with no fault detected. It could come back on at any time since no repairs were made.

The CEL would come on and go off regularly in my old Subaru with 230k miles on it, throwing a code for the cat. I had no intention of replacing the cat because it cost more than the car was worth. Lol

 

[PoMansRam]

I've never had any type of misfire code fix itself, especially if that particular misfire code was a *flashing* CEL one (bad). Then again, I didn't drive it again until it was fixed.

 

[rotwiler]

My truck had bad shift solenoid, threw a misfire code at same time. Hmm, but after shift solenoid was replaced, no more codes, for over year now.

 

[JSMITH8505]

The CEL is like a wife. It'll nag you until you either address it, or until it gets tired of nagging.
Either way, when it goes out, the next time around it'll be worse and you'll really have to pay attention.