Need Help! Code P0306. Already Had Plugs Replaced

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

DanTheMan97

Member
Joined
May 20, 2018
Posts
17
Reaction score
1
Location
Stevensville Mi
I've got a 2005 Expedition XLT V8 5.4L with around 132,000 miles. I had a studder issue and code P0302 showed up. Long story short, I ended up spending $400 to have a shop replace all 8 plugs and the issue had appeared to be solved for the last 5,800 miles. Yesterday while being stuck behind a slow person I noticed the issue again slightly. Was driving about 45mph at the time. Now today while driving I noticed it being very sluggish:suicide:. After purposely pushing the gas pedal hard, but not to the floor, I got code P0306 to show on my code reader. Does anyone have some suggestions? I'm thinking either defective plug/s, a coil pack or possibly even the catalytic converter needs to be replaced. Don't want to throw a $50 coil pack in just to find out thats not the issue.
 

Want3d

Active Member
Joined
Apr 21, 2018
Posts
33
Reaction score
7
Location
Arkansas
I went on amazon and bought a full set of accel coils for 200 shipped to the house that cured my miss. also I've always used motor craft plugs. don't know if that's the case but worth a shot.
 

1955moose

Full Access Members
Joined
Nov 23, 2014
Posts
5,981
Reaction score
1,336
The easiest bet is swap that #6 coil with#5 if code moves, bingo! Did you get a coolant leak near that cylinder recently? Before you plunk out 200 clams try the swap. Also check connection at #6 for corrosion, both at coil, and injector. Corrosion causes misses under load more than anything. A little wire brushing, and some dielectric grease sometimes helps a lot. Let us know what fixes your problem.

Sent from my N9131 using Tapatalk
 

Want3d

Active Member
Joined
Apr 21, 2018
Posts
33
Reaction score
7
Location
Arkansas
also be on the look out for a broken clip at the coil pack if its broke it could be shaking loose and causing the miss
 
OP
OP
DanTheMan97

DanTheMan97

Member
Joined
May 20, 2018
Posts
17
Reaction score
1
Location
Stevensville Mi
Yesterday I just decided to run to O'Reilly's and buy a BWD brand coil pack for about $45, since I already had the old one out. Figure they'll probably will start going bad soon anyway. Sure enough I swapped in the new coil pack and the problem is 90% better. Still a slight mist occasionally, so I'm guessing another is going bad. They really seem to hate this raining weather. For now I'll just keep driving it till another code shows or until the problem gets worse. Ordered a Motorcraft off Amazon today so I'm prepared for when the next one goes out. $35 is a good deal I think, so here is the link. https://www.amazon.com/gp/product/B000IYISWA/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1
 
OP
OP
DanTheMan97

DanTheMan97

Member
Joined
May 20, 2018
Posts
17
Reaction score
1
Location
Stevensville Mi
Code P0306 is showing up again with blinking Engine light. Very sluggish especially while pulling trailer. I tried swapping another coil pack into cylinder 6 as I thought the one I bought may have been defective, but it continues to do the same thing. Please help! What else would you guys try?
 

Latest posts

Members online

Forum statistics

Threads
53,396
Posts
500,653
Members
46,813
Latest member
max357
Top