+1 vote

My truck has about 97,500 miles on the odometer. I recently changed my spark plugs and immediately noticed a vibration at idle and when accelerating slowly that wasn't there previously or at least not as noticeable. It's accompanied by a slight surge in RPMs (no more than 100 RPMs up or down). I'm not a mechanic and am not sure exactly what a misfire sounds/feels like but I believe the vibration and surge may be a misfire. All of the spark plugs were gapped to the correct specification. I thought the coil packs were beginning to go bad. I systematically checked each one. With the truck off I unplugged the wire to one coil pack then turned on the truck. I would listen for differences in sound and feel for differences in vibration. I would then turn off the truck reconnect the wire for the coil pack and turn the truck back on to compare to the sound/vibration I just experienced. When unplugging one of the coil packs there was a slight difference in sound/vibration but not enough to for sure tell me that coil pack is the problem. I then went through the same process removing one coil pack at a time form the engine. I had the same result with the same coil pack. Through this process the engine light came on, I don't remember at what point and threw the 4 codes. These are what the local auto parts store read.

Vehicle: 2007 Ford F150 XLT 5.4 V8 Flex

2 Answers

+1 vote
by (12.6k points)
Best answer
P0350 Ignition coil primary / secondary circuit

P0352 Ignition coil B primary / secondary circuit

P0353 Ignition coil C primary secondary circuit

P0354 Ignition coil D primary / secondary circuit

This means you have the wrong application of the sparkplugs.The 5.4 engine has sparkplugs that are not adjustable. You also need to know if this is a 3 valve engine this will take a special sparkplugs
0 votes
by (7.0k points)

P0350 Ford Code - Ignition Coil Primary/Secondary Circuit
Read more: https://www.autocodes.com/p0350_ford.html

P0352 Ford Code - Ignition Coil 'B' Primary/Secondary Circuit
Read more: https://www.autocodes.com/p0352_ford.html

P0353 Ford Code - Ignition Coil 'C' Primary/Secondary Circuit
Read more: https://www.autocodes.com/p0353_ford.html

P0354 Ford Code - Ignition Coil 'D' Primary/Secondary Circuit
Read more: https://www.autocodes.com/p0354_ford.html

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