My Baby: 2004 Dodge Dakota 3.7l quad cab:
Got truck @99k miles & was decently maintained by previous owner. About a year & a half ago @110k I replaced both valve cover gaskets, because of a leak passenger side & PVC valve & subsequent hoses and that stopped the oil leak totally & apparently helped the vacuum system seal up as well. Had a vacuum leak I am assuming (I hate that word) because it was running noticeably better although it didn't present any vacuum associated MIL codes. Drove from Florida to Kansas twice in 2021 without a hic-up. Being a mechanic of 8yrs with jet engines & propellers in the Navy, I am inclined to do most if not all my maintenance. I have found that one word (assuming) can spend you down a rabbit $$$ hole that has no end. OK I am digressing here sorry.
My Baby @130k miles
Started truck normal & sounded fine and I let it run a few minutes to warm & spread the oil, I never ever start a motor and go, I always let it run a few before engaging. Drove 1/2 miles or so & shut off went into the store. 20 minutes later I try to start & it sounded like it engaged the starter & cut out almost as fast as I heard the starter start & stop. I turned it over & I got it started after pushing gas pedal down quite a bit & I could tell somethings missing. Drove it home & started to do the eye & ear troubleshoot. Just listening to it sounded like it was missing on passengers side, either 2,4,6 cyl. performed code scan & the following codes presented themselves:
P0300 random miss/
P0302 #2 miss/
P2305 Ign Coil B 2ndary circuit

After researching the codes, here we go, I ((assumed) as I think most would when the scanner speaks) I had a bad coil packs &or plugs @cyl #2/#5.
So I went overkill for sure but I plan on keeping her, so I replaced all 6 plugs & 6 ign coil packs. Reset codes and restarted. Sounds the same, it's still missing & nothings changed much, well honestly maybe running a tiny bit noticeably better because of the new coils & plugs but it's still sounding like the original miss cyl's #2 or 4 or 6. I redid code scan and this time the only code to present:

P0113 Intake air temp sensor (assuming) Air intake disassembled to work on coils & plugs

STUMPED
Figured I better check the mechanical sound of the engine with out the fire to listen for mechanical failures. Listening for anything, a tap, tick, crunch, clunk or grinding or anything sounding abby normal, so I unplugged all coil packs. Turned over & fortunately for me, it sounds wonderful & fine turning over without the fire. Not a tap, tick or anything mechanically abby normal sounding. I plugged all coil packs back in and put air intake back together to start back to square one.
I reset code & I started motor and not a single code presents & yet it is still sounds like it's missing. I pulled one coil pack wire at a time restarted & immediately that MIL code for each of the corresponding cyl #'s 1-6 presented. I did this for each of the 6 cyl & wrote downs codes that presented & they correspond to each cyl unplugged. Clearing codes again & having everything plugged back in and air intake reinstalled. Restarted & it sounds like the original missing & no codes are presenting after coil pack & plug replacements. Not like its all that difficult to pull the valve cover on this engine but before I go all mechanical, I am searching out help because I really feel I am chasing a (elecTron) & I have seen some videos in the past but alas cant seem to find the ones about possibly noting other sensors possibly having something to do with the misfiring. Still looking & I have verified that I have spark at each coil pack but not the strength of said spark.
I am stumped.
Any & I mean any advice is deeply appreciated.

 

Swap the ignition coils on 2 and 4, see if the code follows the coil.

 

That's what I thought,
Unfortunately I probably went a little overkill & I replaced all the coil packs and all the spark plugs. At 130k I'm keeping my baby as long as I can and I think I can squeeze at least another 100K out of her so I just replaced all the plugs all the coil packs. Now I'm presented with a p2305 ignition coil b secondary circuit, and a ?0113 which is an air intake code which is a new code probably because I have the intake dismantled so I can work on the coil packs and plugs.
After the replacement I can tell it's running better even though it's still missing like it originally was. So I'm kind of perplexed after replacing the plugs and the coil packs I have to figure out what types of conditions present a P2305 code?
And the original codes p300/p302 are not presenting themselves after the coil packs and plugs were replaced

 

These engines don't do so well with the platinum plugs. You wanna stick with the plain copper plugs, check gaps and change them every 30K. I'd also be careful about aftermarket coil packs. Clear all codes and see what pops again.

 

Read my mind. My first day off of work after 8 days that's exactly what I'm going to do I'm going to start from the beginning resetting the codes and I'll get back to you and let you know. And I want to say thank you for helping cuz this really has me perplexed I'm not a mechanical wizard but I am mechanically inclined used to repair jet engines in the Navy✈️ never liked chasing Tron around but it's not beyond me so I will get back to you again and thank you.

 

Ok cleared codes & put I put it back together and now after starting up no codes are presenting. I pulled all coil packs so it wouldn't fire and turned motor over to listen for a mechanical crunch sound thinking maybe something is broken under valve covers however it sounds fine so I head back to chasing Tron 😑
Still not sure what presents a p2305 code other than the coil packs and all the spark plugs which have been replaced already.

 

You said the code is not showing up anymore. Is it still missing? Drive it around the block, see if the code returns.

 

Drove it around the block, unfortunately no codes present.
Still missing same as what my problem was originally even after replacing all the plugs & coil packs.
I was worried about a mechanical issue and I unplugged all coil packs so it wouldn't fire and I can hear motor turning over but sounds fine & not a peep, squeak or crunchy grinding sound at all. Short of popping the valve cover again (did it last year to fix the leak from both the covers & that perked her up a bunch) which is the last thing I thinking about doing now to rule out a mechanical issues. I am chasing Tron.

 

I'd pop the valve cover off and check the rockers. The 4.7 is prone to knock them off, not sure about 3.7.

Since you did all the ignition system, that leaves fuel system or mechanical fault.

 

Was going to say the same thing. If a rocker ejected though, it should be throwing a misfire code which returns if u clear it.