misfire wtf!?

ok so on my way to pick up my new headers.. (thanks brandon and ej22tim!) i was driving around 80mph on the highway when suddenly my CEL started flashing then illuminated completely. i saw no signs of studdering, spuddering or hesitation or awkard idle or any signs for that matter at all. when i got to meeting them i popped my hood and nothing came loose no vaccuum lines no nothing. after my purchase i went straight to autozone to get a free diagnostics. the reading came back as a misfire in cylinder 4..now wtF....?

I always use shell gasoline when i fill up but this past fill up i purchased holiday gas and used 89 octane (medium level gas) that is the only thing i can think of.

some possibilities are:

bad injector?
bad spark plug?
bad coil/pack?

and a few other things does anyone have ANY insight at all? i hate CEL's with a passion and i notice nothing wrong with my car..

i should had that i own a 98 legacy GT 5 speed with 138k and its a DOHC the car is 100% stock except for my is300 shift knob

 

might be your answer right there

 

Holiday gas is no good. I never fill up on that poop.

 

Never Holiday.

Fill up with BP as soon as this crap is empty.

 

I filled up at shell with v power


But I should add that I was at a 1/4 tank till of holiday crap

After a few
days
should it go away or do I have to erase it? If I have to erase it how do I do it and when I do erase it what if it comes back then where do I start the diagnostic process with the injectors or plugs..wires? And what do I look for in a bad injector or plugs etc more insight please!

 

dude...i frequently used holiday in that car before it was yours and it still ran like a champ. could be one of your other thoughts. i know spark plugs haven't been changed in a while.

could have just been a bad batch of gas...does happen... sucks though, hopefully that beast doesn't need any major work.

 

also, when the head gaskets were re-done by my family friend and airline mechanic---a dude that is SUPER anal--- he said everything looked great on the inside.

 

good. that makes me extra extra happy. and expecially after meeting you. i got good vibes from you aka not a shady dude at all.

8===========================D

ok so after (^^haha) i was reading on nasioc i found this

"A flashing CEL indicates a misfire being detected in real time, unlike a steady CEL which indicates a malfunction has been detected at some point in the past and a code stored.
If your CEL is flashing often you should have it checked ASAP and repaired as needed. There may be a problem with the ignition system (plugs, coils, wires) which left uncorrected can eventually cause other problems such as damage to the catalytic converter from unburned fuel."

this is exactly what happened to me when i was on the highway. it started flashing for approx. 5 seconds then just illuminated completely.

i wonder since the misfire is done and over with and it is not flashing anymore i should just have my CEL reset.

does anyone know how to reset a CEL?

 

LOL--hell yeah man. shady is not my style. that car was perfect... haha, and if my desire to drive fast didn't take over, I would still have it, as it was paid off and maintained perfectly. oh welllz.

well, good luck. Nuke cleared my CEL when I had one from my MAF--I think it was. (car wash got the SPT filter cone wet).

 

have you cleaned the k&n filter recently...re-oiled it and such? just something I thought of.

 

no i put on a cone filter. i like the deep throaty sound i get when i put the pedal down. and i dont think that is the cause considering i put that on over 5k miles ago.

 

i can clear it for you this weekend when i am in town, then disconnect the battery, let it drain down, reconnect it and then restart the car... let it sit and run for a while and i am sure you will be good and gravy.







but never fill holiday again, ever.

 

thanks curly. i appreciate it alot ill send you a PM shortly..

yea holiday gas is absolutely ftmfl. but it was free so i couldnt pass up free gas.

but i can assure everyone that nothing but Shell gasoline goes into my b!tch all the time.

 

you may also try cleaning your maf eric, it looked like you had the wrong adapter for your cone filter....

 

^ would a dirty maf really throw a 'cylinder 4 misfire'? i will surely clean it in the AM. but i just cant see how it would throw a misfire code. but it seems like you know lots so ill give it a try tmrw before throwing in my headers wootz!!!

 

I had a misfire in cylinder 1 because of crappy SA gas. From now on it's BP...invigorate ftw!

 

you will get more codes, with the new header, also.

 

It may be time for plugs/wires/coil, i have a set of 2.5 injecters in rails for cheap if that is the problem too.