2003 Explorer P0303
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2003 Explorer P0303
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Logistics Pro
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From: Cedar Rapids, IA
Since you mention that you swapped the coil and plug and the misfire code remained on cylinder #3, did you clear the codes after the swap? Also, did you look closely at the plugs to see if #3 (original) looked different from #1? Does the engine idle/run like it has a misfire?
-Rod
-Rod
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I cleared the code using a Innova 3130 Scan Tool, started it up and it ran smooth for about 1 or 2 minuets then the code came back and it was running ruff again. The plugs looked about the same, there seemed to be no difference I could see between the two. Thanks
Logistics Pro
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From: Cedar Rapids, IA
Well, if the coil and spark plug don't have an impact and the same cylinder has the misfire, you're looking at either a compression issue on that cylinder, a fuel injector issue, or a goofy way that the wrong amount of air is getting to it.
If you have over 50k miles on the spark plugs that are in it though you might consider changing them out first with new OEM-style plugs just to see if that fixes it. I was amazed how easy the plugs are to change on this engine.
-Rod
If you have over 50k miles on the spark plugs that are in it though you might consider changing them out first with new OEM-style plugs just to see if that fixes it. I was amazed how easy the plugs are to change on this engine.
-Rod
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From: Cedar Rapids, IA
Sadly, the Bosch plugs could be the issue, especially the plus two. If you seriously want to figure this out, before tearing too far in to the engine I'd suggest you either do a compression check on a few cylinders inclusive of #3 or switch all the plugs over to OEM style Autolite or Motorcraft.
I've personally used Iridium single tip plugs in a few newer vehicles without issue, but SEVERAL folks will suggest ONLY using OEM style plugs. I will say that I had misfire issues with plus 2 plugs in the past, replaced them with Iridium plugs and the issue went away. I believe that was in my 1993 Taurus SHO.
-Rod
I've personally used Iridium single tip plugs in a few newer vehicles without issue, but SEVERAL folks will suggest ONLY using OEM style plugs. I will say that I had misfire issues with plus 2 plugs in the past, replaced them with Iridium plugs and the issue went away. I believe that was in my 1993 Taurus SHO.
-Rod
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probably no surprise but it also has a P0316 mis-fire at start up. I'm hopeful to get the plugs switched today or tomorrow so I can get this fixed!!!Thanks
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Well Thanks all for your help on trying to help me with this problem, except I unfortunately need to look at the manual first and see exactly what order Ford puts its cylinders. Evidently the old odd even banks of cylinders is gone and now right is 1-4 left is 5-8. I pulled the correct #3 cylinder and sadly the boot has anti-freeze on it the plug looks corroded. Hopeful its just the intake leak and not more serious. I guess I have a weekend project cleaning out the hole and investigating farther.
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From: Cedar Rapids, IA
You're correct, the numbering is Bank 1 is 1-4 and on your Explorer, that is the bank on the passenger side for a US-spec truck. Bank 2 will be 5-8. Both banks start at the belt and cylinder count increases as you move towards the firewall.
-Rod
-Rod
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