While running the 8 hard, a flashing CEL came on for about 5 seconds and then shut off. I know this may be a very broad question, but can anyone give me some ideas what could cause that??

i read all the possible causes of a flashing CEL, but nothing spoke of it shutting off within seconds.

 

misfire. how old is your ignition?

 

27lk miles on car, new plugs. I have the new c coils and wires, just havent installed them yet.

 

change your coils and wires. might as well clean maf and ess while you are at it

 

I would do the coils ASAP then.

Misfire will destroy your cat quickly if you don't fix it.

 

A flashing check engine light is not only a misfire, but a catalyst destroying misfire. Basically a misfire so bad that damage can result from the misfire.

As others have suggested, its time to inspect and replace the spark plugs, coils, and I would also suggest replacing the wires. Inspect the air filter for good measure and ensure there is no oil in the intake boot.

 

It usually shuts off within seconds since you can't really maintain high load high rpm without needing to let off the throttle to change gears.

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This was the first and only time it did it. I didnt notice or hear anything abnormal when it did it. Does that have any significance?

 

Not really. Misfires are a silent killer.

 

Just put in new coils ASAP.

 

Working to get it done. I am not going to drive it until then. I do have to travel 25 miles to bring it to Kris when he is available. Will driving slower or normal help in preventing another misfire?

 

Another question, will a code show up if tested even though the CEL is no longer on?

 

There could be a pending code if it is still happening. A pending code is stored but not displayed until the ECU is sure it is happening.