Flashing check engine light?
 

First things first. I have had the plugs and spring caps replaced recently. I run 91 octane fuel, pretty sure there is no water in my fuel. Just changed the fuel filter, oil, and antifreeze w/ flush. Tranny has been flushed recently w/ new filters. I do not have a programmer installed, it will be back on Friday. My check engine light flashed or flickered for a few secs but did not stay on. I was going up a slight hill and could feel it kind of hesitate. It did this twice but the light just flashed but did not stay on. It has did this before without the check engine light being involved. Pretty much on the same spot of the highway. Any clue as to what it could be? I was thinking maybe coil pack but I really do not know. Please help! Thanks in advance.......

my truck was doing this last summer. I had a bunch of things done but only 1 thing fixed it. List of things i had done

Air Filter
Fuel Filter
Spark Plugs
Oil Change

I would never do a tranny flush have always heard bad things about the flushing part from a tranny guy i knew. I got mine drained and they added that instant shudder fix with new oil. That was the key fixed it immediately.

Also i did have some water in my coil plugs once from the dealership washing the engine bay with a powerwasher. That engine cannot take that, the water gets in those coilplugs. You can take them off pretty easy and spray some stuff down there and let them dry out.I think its di electric grease you can use.

I have had the tranny done for about 7000 miles. Plus the Lucas Tranny additive. I was thinking maybe it has something to do with the TC because I have 4.56 gears and my programmer is not installed yet to make the tranny shift properly. Maybe that is the reason? Other than that, everything runs smooth and up to par as far as I can tell. Like I said before, everything has been done as far as maintenance.

A flashing check engine light means ONE THING, and ONE THING ONLY: Engine misfire that has the potential to damage the catalytic converters.

Nothing else will cause the check engine light to flash on and off.

Thanks Cody! I just ordered a complete replacement Platinum Coil Pack (8). They have a 5 yr. unlimited mileage warranty. I figured I might as well replace them all since I just barely replaced all the spark plugs and spring caps. I got a good deal too! $141.20 from Auto Parts Warehouse. Hopefully that fixes the problem and just for anyone else, I have had my fuel system and air system cleaned. So there is NO reason to believe that my TB, MAF, or fuel filter is the cause especially since they were cleaned by a professional and the filter was replaced yesterday prior to the before mentioned problem. ;)

I am still planning on replacing all the coil packs. I am kinda stumped. :confused: I went to Auto Zone and had my truck scanned for codes. Guess what!? No codes found. (Pass) This seems weird to me considering my check engine light flashed on two separate occasions. What is up with that? I believe that my truck misfired but why no codes? If there is is something serious that could be wrong, why no code? Hmmmmm........ :cursin:

it flashes everytime it senses a miss fire but will only set a DTC if it miss fires for a prolonged amount of time. I'd also suggest pulling the plugs just to insure they are not fouled any.

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I just changed all 8 coil packs on my truck and still there is a misfire w/out detection. I heard it could be the camshaft position sensor? I al so just changed the spark plugs and spring caps a few weeks earlier. Now what do I do? Without a code, I am waking in the dark......