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Old 06-13-2006, 12:00 PM   #1
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Default DTC P0303, P0300... Flashing Check Engine Light

Thought I would share my experience.

Last evening I was on the highway and was on it pretty hard for a moment getting up to speed. Check engine light started flashing and then I realized the car seemed to be misfiring. Slowed down and the light kept flashing, misfire was less noticable...still there.

The flashing check engine light is considered very bad. Per another gearhead who was able to look up the flashing light, it means there is a misfire condition bad enough to damage the catalytic converter if run for too long. I pulled into a parking lot and looked things over, finiding nothing

Car runs horribly and check engine light is flashing. Having a mechanic as a best friend and having experience with this type of thing, I limped home slowly and gently.

Diagnosing the issue I check the plug by swapping with another, no change Looked over the wire for any signs of external damage, then swapped the coil pack. The coil pack seems to have been the bad part.

Odd thing is only cylinder 3 logged the misfire code. Since one coil fires two plugs, I would expect that the #6 cylinder would have also logged misfires. One other thing I noticed was that the bolt hole is stripped on the engine side of my 3/6 coil and I will be repairing that (somehow) very soon.
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Old 06-13-2006, 12:43 PM   #2
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Good thing you have gearhead friends that you can call in the night, though apparently you had to get it home to fix it.

I was wondering about the stripped bolt hole on the 3/6 coil. I guess I am not sure what that means. Enlighten me.
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Old 06-13-2006, 01:07 PM   #3
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Glad you got it home before causing any damage!! That stripped hole though, does it looks like a J/B Weld kinda thing or is it something that you can entirely replace? Either way I know you'll come up with a genious fix!!

BTW what is it with your car and bolts? breaking, stripping....
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Old 06-13-2006, 03:56 PM   #4
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Longer bolt w/ nut & washer on other side. How does the coil ground out the engine for the sparkplugs? Is it by the bolt holes?
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Old 06-13-2006, 03:58 PM   #5
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The coil grounds are the right hand bolts on the coils. I just cleaned mine yesterday and it seems to run much smoother.
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Old 06-13-2006, 04:15 PM   #6
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My first call to a GH didn't work out well as he has his books at work to help BC members.

The second guy was slightly helpful once I pointed him in the right direction.

The bolt.. well...you see. I must have overtightened it a couple times tryin to ensure the best ground. The mounting plate is extremely thin and aluminum I think.

Hmmm what do to..... put on the spare that I have or fix the other one? It'* a tough decision.
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Old 06-13-2006, 04:20 PM   #7
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Put the spare on and fix it later. Usually what I do when I have spare parts.
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Old 06-13-2006, 04:32 PM   #8
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Now...do I still have the spare? hmmm
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Old 06-13-2006, 04:39 PM   #9
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Or did it go in a box out to someone???? Hmmmm........

Could you possibly look into a conductive grease? Seperate ground strap from the coil to the engine block?
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Old 06-13-2006, 04:44 PM   #10
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Originally Posted by Cheetah
Or did it go in a box out to someone???? Hmmmm........

Could you possibly look into a conductive grease? Seperate ground strap from the coil to the engine block?
Nah....I'll have this fixed up in a jiffy. And if I can't find my spare..I'll swap it with Vptrumans when he'* up on Sunday... (now all I need to do is distract him for 5 min)
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