FX4 Matt
You sir, are correct, plug #5 was toast too, new set of plugs on the way, those autolite HT0 are a pain in the **** to get ahold of. Gonna have to run a couple of motorcraft plugs for a few days until I can get those ordered in. Going back to the tuner on Wed. and see what we can get figured out.

 

FX4 Matt
Where did you get your GMS coils and were they worth the money?

 

I Knew it had to be a plug!, as for the plugs look on line I have found them for as little as 80 a set, and I got the COP's from Troyer Performace the COPs are great no issues

 

Has any one had problems with octane boost possibly fouling plugs?? I have fouled out two sets now. The tuner has had the pickup for weeks now and can find nothing wrong. Two other shops have had a crack at it as well and can find nothing wrong?!? Everyone I talk to tells me it can't be the fuel, but this all started just after I poured in a bottle of octane boost. Anyone else heard of anything like this???

 

Yep if you use the search feature, you will find a few post from people asking for help after using off the shelf octane boost in their F150 5.4 3V.
Torco being the exception

 

I looked around and I see some people have made it through with a spark plug change, has anyone had to drain their tanks? I am at wits end with this thing, bad fuel is about the only thing left and unfortunatly I have a full tank in there right now.

 

Who is your tuner?

 

Drained the tank today and put in new fuel, runs fine now. Lesson learned on the octane boost!! Apparently it is vile poison to my truck. I can hardly believe that it would foul plugs out that fast but it runs like a champ now.

My tuner is Dynotune, a somewhat local shop. The owner is a damn decent guy, I wish I would have took it to him right off the bat, but I let the dealership and another shop I've used in the past mess with it forever.

 

That is strange, I have used oct boost many times with no issues.

 

Yeah, it seems weird, but 20 miles after I dumped it in I started missing. Truck seems better now, but I am getting a ignition coil primary/secondary code on 4 and 6 and a very random miss. Hopefully I just need to clean the connections. If I need to replace plugs again I may scream.

 

Ok, now I am getting the cop fault codes on 4 and 6, so I moved #1 to #4 to check that cop and sure enough I get a code on #1, but I still have a code on #4!! Can a bad plug cause that code (P0354)? Or do I have a problem with the harness or what??

 

did you swap out the cops?.. this may help
P0354 - Ignition Coil D Primary/Secondary Circuit
Description: See the description for DTC P0350.
Possible Causes: See the possible causes for DTC P0350.
Diagnostic Aids: See the diagnostic aids for DTC P0350.
Application Key On Engine Off Key On Engine Running Continuous Memory
Coil-on-plug (COP) ignition testing — GO to Pinpoint Test JF. GO to Pinpoint Test JF.
Coil pack ignition testing — GO to Pinpoint Test JE. GO to Pinpoint Test JE.

P0350 - Ignition Coil Primary/Secondary Circuit





Description: Each ignition primary circuit is continuously monitored. The test fails when the powertrain control module (PCM) does not receive a valid ignition diagnostic monitor (IDM) pulse signal from the ignition module (integrated in the PCM).
Possible Causes: Open or short in the Ignition START/RUN circuit
Open coil driver circuit
Coil driver circuit shorted to ground
Damaged coil
Coil driver circuit shorted to VPWR

Diagnostic Aids: Use the 12-volt non-powered test lamp to verify START/RUN voltage at the ignition coil harness connector.
Check the coil driver circuit for open, short to VPWR, or short to ground.
Application Key On Engine Off Key On Engine Running Continuous Memory
All GO to Pinpoint Test JE.


Vehicle Related DTC Cylinder Number Ignition Coil Coil Driver (CD) PCM Pin

F-150, Mark LT P0351 1 A A E17
P0352 2 B D E11
P0353 3 C B E12
P0354 4 D G E14
P0355 5 E F E10
P0356 6 F E E15
P0357 7 G C E16
P0358 8 H H E9

 

Thanks, I need it to warm up here before I dig in too deep, -30 windchill today. By the way, what gap are you running on your plugs?

 

I have the HT0's I didnt mess with the gap.

 

I have the exact same prob. 06 5.4 K&N cai 1 inch high rise street 40's.
Yip idles just fine. Under load what a MUTT. I am going to try and add 1-2 degrees advance spark on my Predator.
After that its a new set of plugs. If you find out the prob. I would like to know. Billings MT. Thanks