Hello,
I have a 2000 Dodge Durango 5.9L that just hit 170K. I have read other
threads with the misfire issue but I think mine might be a little
different. The truck started running a little rough and the engine light
came on. Got it checked out and got P0300 and P0308. I changed out the
plugs and wires and now getting P0302. Next I changed out the
distributer cap and rotor and still getting P0302. Thinking it might be
bad gas or a clooged fuel injector I let it run idle for a while. When I
returned it was running smooth. I got in and drove around the block and
it rode fine. So I go get half a tank of premium gas and a couple
bottles of fuel injector cleaner. Still driving fine I decided to drive
it to work. It drove fine until I was just down the street from the
office when it started missing again. Went to lunch and still missing.
On the way back from lunch it ran smooth. On the way home it drove fine
until I was a mile away from the house and it started missing again. You
feel it stutter or like it wants to cut off driving at 20mph or 50mph.
Still getting P0302 so I decided to switch out the fuel injectors
between 2 and 4 hoping the misfire would go to #4 but I ended up getting
a misfire on P0305, P0302, P0306 and P0308, nothing on #4. I cleared out
the codes to see if I get the same ones back. Again I let it run idle
for a while and noticed it was running smooth again. It drove fine for a
day and a half and it started missing again. This time I'm getting
P0306. I switched out the ignition coil even though the resistance
checked out fine. Again it drove fine for a while and started missing
again. It's frustating because the codes keep jumping around and it runs
smooth one day and misses on the next. I have read on other threads to
check compression, but I really think it's fuel related. I will try to
check the fuel pressure this weekend and see what I get. Also I changed
out the water pump and timimg chain a couple years ago. Any help will be
greatly appreciated.
Thanks.

 

What plugs did you use? Did you disconnect your battery before doing the work? Try resetting your PCM with the battery disconnect.

SJ02

 

I used Champion Copper spark plugs. I did not disconnect the battery. I will try to reset the PCM when I get home today.

 

While you are at the battery, go ahead and clean the posts and make sure the wires are in good shape too.

SJ02

 

Will do. I try my best to keep that clean and tight, but you never know.

 

My battery was old and load checked at 76% but that was not enough for for my D. New battery and all kinds of weird codes stopped.

 

I reset the PCM and after starting her up it ran smooth for a few minutes and then it started missing. The connection to the battery was tight and clean. I will try and drive it today and see what code I get next.
The battery is about a year old, but will get it tested.

 

Did you restart it 3 times without giving it gas? After I changed my plugs, I got a misfire on Cyl 7. I changed that plug and haven't gotten another one. If it continues, try changing the plugs again, and check the gaps on the new ones.

SJ02

 

I'll swap out the even with the odd side and see if the misfires jump to the other side. I double check the gap even after they told me they were already set.

 

Well after further troubleshooting I swapped out the spark plugs with the other side. I broke one getting it out. Once I replaced that the truck started running fine and has been since Saturday. I put over 50 miles and so far so good. Let's see.