Flashing CEL Briefly
 

2014 V6 Auto (LFX engine) with 58k miles. Bought it used with 40k on the clock.


Situation: Drove to a wedding which was a 35-minute highway drive away. I was on it pretty good (90-105 most of the way). On the way back (about 25 mins in), my CEL started flashing. I was on it pretty good on the way back as well. Once light started flashing, I let off the gas completely (was doing 80-90 at the time, I'd say). It stopped flashing for a few seconds, then started again. After flashing about 4-5 times, it stopped completely. After coasting down to 50, I exited the highway. With the light off and the car running just fine, I jumped back on the highway, hit 100 and wide open throttle, and no lights, sounds, or anything out of the ordinary.


History: Stock everything (save for an oil catch can). On the way to the wedding, it did lurch one time when I let my foot off the gas, almost like a hard downshift or something.


Actions Taken: I threw my reader on there this morning (the next morning). Only one code: P0303. I swapped the 3 coil with the 1 coil and went on a 30-min drive, mostly on the highway. Hit 95 and didn't experience any issues or lights. No codes after the test drive.


This ever happen to anyone else, or does anyone have any ideas where I should start? At this point, I'm inclined to just ignore it since everything is working just fine, but I know what I saw, so something obviously was out of whack at some point.

I'd wait till it does it again...

That's how I'm feeling as well. I may go ahead and purchase a set of plugs and a new coil (found an AC Delco ignition coil on Amazon for $50+) just for kicks. The maintenance schedule for plugs is 97k miles, but what the heck. Will give me something to do next Sunday, anyway.


Oh, reason being on the coil is that I texted my mechanic buddy, and his first thought was possibly a bad coil. He hasn't seen or diagnosed the car since the incident, though, so it's just a hunch on his part.

I would be concerned that an "AC Delco" coil on amazon would be counterfeit. If you get it, put in on a cylinder unrelated to one that you have had problems with. And keep you pull off in the trunk as a back up you get you home. If it was me, I might do plugs but would likely just drive it to see if the problem follows the coil swap.

Interesting. Is it recommended to get an OEM ignition coil at the dealership (most expensive), or perhaps an OEM off rockauto (medium expense)?


I think the dealership has them for around $100 a pop if I recall. Rockauto is in the $70 range. All in all it's not a big hit for me at the moment, so I was just paying for insurance and peace of mind. I hate that I don't know how to diagnose it, though.

I haven't seen any problem with counterfeit items from RockAuto. For electronics, I try and stay away from the total "no name" brands, but would likely pick a Delphi or NGK on RockAuto over Amazon "Ac Delco". Maybe if it was sold directly by Amazon I might be ok with it, but a lot of the cheaper car parts are sold by others.

This applies to Ebay also. I buy a lot of stuff from Ebay, but I stay away from most of the car parts on there.

Use a good fuel injector cleaner for one tank before you do anything.
You were @ WOT.

Yeah, I have some cleaner sitting on my stand. I'll put that in there. As far as wot, I wasn't punching it when the light started flashing. In fact, I think I only punched it 2 (maybe 3) times the entire drive. The last one was after I exited the highway out of concern only to realize that the light is no longer flashing and the car didn't sound or fall off in any way, so I thought I'd test it.


I've driven it a couple of times since then w/o any incident.