germanshepherd

had new muffler installed today, flowmaster, sounds great. was merging onto traffic under heavy accelerating and the CEL came on for about 10 seconds then went off. Truck seemed to run ok and was still pulling but when the light came on, I slowed down once safe to do so. it ran fine for the next few miles until I got home.
I feel as if I did not floor it, the light never would have come on and would not have known of any issues.
Is this a coincidence it happened after i got the new muffler installed? I dont think I really floored it like this before either so not sure if this would have happened anyway today with the stock muffler.

I had the throttle body/maf cleaned, fuel filter and air filter changed a month ago, it has 70k miles, original plugs as far as I know. always ran fine and I did go heavy on the acceleration before but today I had it hammered down to get onto the busy highway prob more so than in the past. looks like the common reason for blinking CEL is misfire. if they damaged a sensor during the install, would that cause the light to be on more often? it just came on once and for about 10 seconds and went off. thanks

Especial86

iTrader: (1)

You have a misfire.. Could be a plug or a cop.. I highly suggest just changing all the plugs considering they are original, and while your at it throw some new cops in there too.

If your a 5.4 then get the sp515 plugs

The accel cops work great and cost under $200 for all 8..
Your muffler has nothing to do with it.. It's probably the new sound that has you putting the hammer down, which revealed the age and condition of your plugs and cops..

Save your old cops and use them as replacements if the accel cops start to fail... For the price of just 1 or 2 wild goose chase cop misfires, your much more better off just starting with a fresh set of 8, then keep the originals as replacements.

germanshepherd

thanks, that is what I was thinking as well. you are probably right on the new sound as that was part of me doing the heavy acceleration (still had to in order to merge but I think I gave it some extra punch to hear it roar).
I was going to get the plugs etc done anyway but wanted to save up since my local shop said they can do it for about $300 but if any plugs brake, then it can be up to a grand depending on how many brake. they are pretty good at getting them out though but did tell me worse case scenario.

I am not doing any damage am i if I just drive it around normally and the light does not come back on?

muddyford911

iTrader: (1)

Not trying to bash especial's advice, but of the 3 ford trucks I've owned, 95' 03' and '08, none of them have accepted aftermarket ignition components very well. It's always a good idea to use OEM ignition components if budget allows. Accel coils are great if you're in a pinch and short on cash, but motorcraft is the most reliable option.

germanshepherd

P0305 is my error, 5 cylinder. My shop said coils alone are 95 bucks each. Not sure what brand.

germanshepherd

Shop does not use OEM coils. I can't afford coils and plugs. If coils are fine and I just get plugs, is it a lot in labor to do coils down road?

Especial86

iTrader: (1)

No worries on the bash, I hear what your staying..

The accel coils have been in my truck trouble free for over 60k miles. 26k of which have been supercharged. So I can personally vouch for their quality.. For the price they can't be beat..
The OEM cops are very pricy unless you get a set off eBay that are take offs.. But even then your rolling the dice and potentially ending up with a bad coil in the bunch..

germanshepherd

read nothing but positive reviews on the accels online for F150 owners. I can get those on ebay for under $200 or autozone for about $350, still a lot cheaper than the fisher auto parts ones my garage would use.
I will go with the accels based on the positive review and also your experience but do appreciate all of the input from others.. thanks

uzikaduzi

i had a crack on my intake manifold that leaked coolant into the plug valley on my 4.6l... it was quite similar to your description. it didn't leak enough coolant to really see and i was getting something like a p306 (cylinder 6 miss-fire) i changed the coil and it went a way for a few days, then came back which is when i noticed the coolant.

03Mach1

Well maybe I'm old school but I would rather go about the repairs by diagnosing the problem properly in steps vs. spending a lot of money and just throwing parts at a problem and hoping it is fixed.

I would pull the # 5 plug and look at it. Plugs in a computer controlled vehicle should be good for 100k. If you think the plug is the issue then go ahead and replace them all. Since you did get a misfire code I would check the #5 COP with a multimeter and see what you get. If the coil checks out then just put everything back together and drive the truck. Get on it a few times and see if the misfire comes back Before you start tossing more parts at it.

The misfire happened once unde f a hard load. The truck still runs and idles fine and you didn't get multiple misfire codes. Why spend $300+ when your not even sure where the problem lies.