Sorry for long post. Need some help. Got a 2010 with 4.6 vin 8. 302k. it has bad misfire i have been chasing. Cylinder 1. Has 3 codes p0301, p0457 and p0420. Both New bank 1 O2 sensors. Injector, coil and plug have been replace. Plugs had 30k. Swapped coil to different cylinde same problem. Reset computer each time i moved it. Every morning i start the truck and drive a couple miles, cel flashes and misfires badly. Drive to the store a couple miles away, and come back out start truck cel still on but not flashing. Still has slight misfire and then drive 66 miles to work at 85mph no problems. Fuel mileage is at 16.5. Truck isnt down on power or sluggish. But after the drive the cats are very hot. Been 2k miles since problem has started. Bad cats? Or any other ideas?

 

You need to figure out why cylinder 1 is misfiring and the rest of your issues will likely vanish. There are 3 conditions for proper cylinder combustion, Fuel, fire, and compression. Any one of those items not present will create a misfire.

If you allow your engine to misfire much longer, you will also be buying new catalytic convertors. I suggest you find someone qualified to diagnose the misfire before it digs deeper into your wallet.

 

Its a company truck. I play mechanic when i have time too.
Im not worried about cost. Im pretty sure cats are bad. I dont know the quirks of these trucks

 

Soo, what's your motivation to fix such items. I'm a professional auto tech with over 40 years of training Ford specific. More than willing to help you out of a tight spot. NOT willing to walk you thru years of training I endured or indulge your curiosity.

 

Its my daily. Its a construction company with a small engine guy that does the basic stuff. Ive research several forums. Havent really found anything the same as with what i have. Asked for ideas not walk throughs.

 

Idea #1 Find someone that can put tools and hands on to determine cause with minimal costs.

You can inquire in online forums until your eyes bleed and never get any further than you are now. Don't mean to be so blunt but it is what it is.

 

some of us wonder why you are even here.

if you don’t want to help, then don’t. But then why be here?

to come and brag about how much experience you have and then refuse to help is absolutely asinine. Why bother? Does it make you feel good to tell someone “I could fix this, but I won’t because you didn’t earn it”

I don’t get you .... and I’m not the only one.

this is a community for those who need help, and those who wish to help. If you don’t fit into either category, then this is not the community for you.

if your version of helping is to come on here and tell everyone to seek out help from people who paid for the training and are unwilling to share it without compensation, then that is of no help to anyone - so don’t bother. If you haven’t noticed, no one stops to worship at your alter of experience.

If you really are as good as you proclaim to be, you could be a very valuable member if this community. But instead, with your unwillingness to help, well ..... you aren’t.

 

Flashing CEL is a good indication of random multiple misfires. I would suspect you have worn out plugs or bad boot springs. Hopefully this isn't caused by improper use of dielectric grease.

 

Pull the spark plug out you replaced and inspect the ceramic insulator closely. It's very easy to crack them when installing.

 

Say what?

His advice is spot on. Not everyone is cut out for this and that needs to be addressed.

OP is firing the proverbial parts cannon and has no earthly idea how to troubleshoot his issue. Who buys injectors and O2 sensors for a misfire before even doing a compression test for said misfire?

A bad tech lights other people’s money on fire and gets sent to the unemployment line over it.

 

As mentioned above any and I mean any side load will crack the porcelain. This means don't allow the socket or extension to wobble. I have pulled all the plugs out of engines that someone just changed only to find them all cracked. This is really common on the 5.0 coyote for some reason.

 

Quite common on all of the modular engines. I think the surrounding wall of the plug well gives people too much confidence they are putting them in without a chance of damage. I fell into that trap myself the 1st time I changed plugs on a 4.6.

 

Because i had those codes. And my shop has extra of thise parts because theres more than one f150. Whats the point of the forum when the help offered is take it to shop? Dont want to help dont comment

 

just recently change the plugs, last guy had the truck before me went 260k on original plugs and was giving it shifting issuse. But you got a point with the coils. Went i did the plug, i only replace 2 bad coils. Didnt check the others