Flashing check engine = misfire?
 

On the way home tonight, there was a brief stint where the truck ran a little rough on the highway and the MIL was flashing. After about a 1/2 mile, I could feel the truck smooth out and the light stopped flashing and just stayed on. I guess my first trip tomorrow will be autozone for a code scanner. Any guesses?

What kind of truck and how many miles?

05 FX4 5.4, about 79K on the odometer.

I have heard that when the lite flashes it could mean a possible catastrophic condition. That being said and the truck being an 05 you might want to pay attention to the injectors.

Just a thought.

No, flashing is simply a misfire.

I'm still on the stock plugs so it's probably about time to change them, though I would think that if one of them fouled out, the truck wouldn't run rough, then smooth out. So far it runs fine and the light is still on, but I need to get over the the Vato Zone this afternoon to get the codes pulled.

Where did everyone get their plugs? Ford dealer?

advanceautoparts.com

Part number - SP507

coupon a123

$47.00 with tax....picked up in the store.

going to be a misfire....change your plugs and COPS. One of those is bad causing a misfire on one of your cylinders.

Im having the shudder at idle occasionally and will be changing my COPS on Wed and checking my plugs and fuel injectors for damage. I had my plugs changed about 20K miles ago though.

Not really looking forward to the plugs, but COPS aren't hard. where's the best place to pick them up?

EBay....Global and Uneek sell them.....
http://http://stores.ebay.com/GLOBAL...=p4634.c0.m322

Miss firing plug/plugs my guess, bad COP would do it all the time.

I've finally got time today and I'mm going to Advance to pull the codes shortly. I've been driving pretty easy since the light is still on, but I had to step on it on the highway to merge today and the truck started breaking up in the higher rpms and the light started flashing again. Once I eased off and cruise about a 1/4 mile, it smoothed back out and the light stayed solid.

Back from Advance. The only code present was P0302 - Cyl 2 misfire. Probably the COP?

Alright, so after searching for the term p0302, I found rockpick's thread where he had injector troubles and also got that code. I'll add that in my situation, I've had instances where the truck would be very hard to start and i've had to crank for longer than normal to get it to turn over. I suspected it was injector related but wasn't sure.

so the culprits could be:

1. plug - possible, but not likely

2. COP - probably

3. injector - possible

How would one test to find out which one's the problem?

My truck pulled a P0302 awhile back.....water had leaked around the boot and onto the spark plug in cylinder #2. Don't ask how it happened... =)

If you think its the COP on the #2 cylinder. Switch the #2 and another COP and see what code you are getting. This would let you know if it is or is not the COP itself.