P0302 Error Code – Misfire Cylinder #2
10-02-2014, 02:31 PM
#1
P0302 Error Code – Misfire Cylinder #2
Since I am new to this forum I thought a good way to introduce myself would be to present a problem and a solution. Hopefully this is helpful to someone struggling with a similar issue.
Just recently I drove my truck (2006 F150 V8, 5.4L) for the first time in a month. I had been away on a trip and during my absence it had rained heavily on several occasions. About a half hour into my drive, the engine started running really rough and the check engine light came on. After getting it back to my garage I put my OBD2 scanner on it and come to find it’s throwing a P0302 error code, misfire on cylinder #2. Further observation with the scanner revealed high LTFT’s on Bank1, roughly 19.0 to 29.0 values. Normally they’d be under 10.0. Just a side note, two years prior to this occurrence I had replaced all the injectors on Bank1 due to a misfire problem, which BTW resolved the issue. Thus I was pretty confident that it wouldn’t likely be a bad injector.
I pulled the COP on cylinder #2 and discovered that the boot was soaking wet and the spark plug well had about a ¼” of water in it. So, I cleaned out the SP well and cleaned up the boot and applied new dielectric grease to it and reinstalled it. However, before reinstalling the COP I used a Standard Ignition Tester (KD2757) to verify that I had a nice hot spark. There was no need to pull the plug, because the culprit was obvious. Cleared the code and truck ran normally again.
It’s interesting to note, that I ran into this issue once before when I made the mistake of shampooing the engine. The spark plug wells all filled up with water and I had to pull all the COP’s and dry everything. I’ll never do that again.
Hope this was helpful to someone. Having a scanner makes all the difference when you’re searching for clues.
Just recently I drove my truck (2006 F150 V8, 5.4L) for the first time in a month. I had been away on a trip and during my absence it had rained heavily on several occasions. About a half hour into my drive, the engine started running really rough and the check engine light came on. After getting it back to my garage I put my OBD2 scanner on it and come to find it’s throwing a P0302 error code, misfire on cylinder #2. Further observation with the scanner revealed high LTFT’s on Bank1, roughly 19.0 to 29.0 values. Normally they’d be under 10.0. Just a side note, two years prior to this occurrence I had replaced all the injectors on Bank1 due to a misfire problem, which BTW resolved the issue. Thus I was pretty confident that it wouldn’t likely be a bad injector.
I pulled the COP on cylinder #2 and discovered that the boot was soaking wet and the spark plug well had about a ¼” of water in it. So, I cleaned out the SP well and cleaned up the boot and applied new dielectric grease to it and reinstalled it. However, before reinstalling the COP I used a Standard Ignition Tester (KD2757) to verify that I had a nice hot spark. There was no need to pull the plug, because the culprit was obvious. Cleared the code and truck ran normally again.
It’s interesting to note, that I ran into this issue once before when I made the mistake of shampooing the engine. The spark plug wells all filled up with water and I had to pull all the COP’s and dry everything. I’ll never do that again.
Hope this was helpful to someone. Having a scanner makes all the difference when you’re searching for clues.
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tonya runnels (02-25-2018)
10-29-2014, 08:37 AM
#2
over time the coil on plug boots shrink and dont seal out moisture as well. they can be replaced for fairly cheap. my old 2v expedition was plagued with getting a drip down onto the #4 cylinder COP hole and causing a misfire when i would wash the car. i could never figure out how/where it was coming from... my wife had the car washed once and i had to get it towed home after the dude used a pressure washer near the hood/firewall seal... also it doenst help on some 5.4's that ford routed the heater core hoses directly over the ignition coils... so any leak there usually causes a misfire as well.
nice work with the diagnostic tools. i use a elm327 bluetooth odbii tool with the "torque" app on my phone to read live data, fuel trims, etc. its a lifesaver to be able to see whats going on with your car more than just sitting around waiting for a code to show up and by then they usually dogpile on each other.
nice work with the diagnostic tools. i use a elm327 bluetooth odbii tool with the "torque" app on my phone to read live data, fuel trims, etc. its a lifesaver to be able to see whats going on with your car more than just sitting around waiting for a code to show up and by then they usually dogpile on each other.
