Need help
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3rd Gear
Joined: Jul 2025
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Need help
I just recently got my 5.4L 98 f-150 Lariat. have had some misfire problems but most went away with a new MAF sensor, however I have code P0306 and I’ve changed the coil,plugs, and plug wires. I do wonder if anyone knows what order the wires go onto the coil packs? It doesn’t have the coil on plugs, it’s got the two seperate coils in front and I can’t find anything about what order the plug wires should be on the coils. I also think it has a vacuum leak as I can hear a hiss near the throttle body when it is revved. Thanks for any help.
Fleet Mechanic
Joined: Jun 2023
Posts: 1,352
Likes: 373
From: WA
Found this on the internet, link below. Compare to what you have before pulling wires. But, as far as your misfire, if one is wrong then there should be another that's wrong. One coil fires two cylinders. Each coil pack has two coils inside it.
It's for the 4.6 but should be the same. The 5.4 with wasted spark (coil packs) seems to be an oddball. Can't fnd much about it. Rockauto shows it as COP.
Good luck.
It's for the 4.6 but should be the same. The 5.4 with wasted spark (coil packs) seems to be an oddball. Can't fnd much about it. Rockauto shows it as COP.
Good luck.
Thread Starter
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3rd Gear
Joined: Jul 2025
Posts: 3
Likes: 0
Found this on the internet, link below. Compare to what you have before pulling wires. But, as far as your misfire, if one is wrong then there should be another that's wrong. One coil fires two cylinders. Each coil pack has two coils inside it.
It's for the 4.6 but should be the same. The 5.4 with wasted spark (coil packs) seems to be an oddball. Can't fnd much about it. Rockauto shows it as COP.
Good luck.
https://www.pinterest.com/pin/812336851529350296/
It's for the 4.6 but should be the same. The 5.4 with wasted spark (coil packs) seems to be an oddball. Can't fnd much about it. Rockauto shows it as COP.
Good luck.
https://www.pinterest.com/pin/812336851529350296/
thank you, I wasn’t sure if they were the same so I’ll compare, it is definitely an oddball though. I’m gonna look at the vaccum lines tomorrow, I was told when I bought it that the injectors were new but I’m probably gonna check it anyway and see if it’s clogged
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3rd Gear
Joined: Jul 2025
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It seems to prefer this order on the coils, when routing the plug wires like the 4.6 above it has no power what so ever, I’m still getting a misfire but upon looking up under the truck I’ve noticed an exhaust leak that needs to be fixed as well
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Fleet Mechanic
Joined: Jun 2023
Posts: 1,352
Likes: 373
From: WA
Anyway, sounds like you're finding things to fix. Good luck.
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