Went from scratching my head.......

To hitting it against the engine.....

Started with a P0301, swapped coils and ended up with a P0302 for a misfire.

Next, replace the coil.....P0302 goes away, now I end up with a P0306.

Replaced all plugs with a tuneup already.

Am I missing something here?

How many miles? Did you use the recommended copper core plugs? Could be another bad coil (they don't last forever) or just a bad tank of gas?

Probably not related but I had a p0306 one time that actually caused the CEL to flash. I shut it down immediately cleared it and tried restarted it a few times and it persisted. Let it sit for about an hour and started it up and it has never come back.

Maybe I should just go to replace the lot of coils and see how it goes.

She's got 188k on her now, it just seems to crop up again once I fix the initial problem.

Replaced the Cam and Crank sensors, got rid of the multiple misfires. Found the bad coil, replaced it, and a new error popped up.

Did you use Mopar crank and cam sensors? If the coils were original it may be a good idea to swap them and see. The old ones don't owe you anything after 188k. I've heard the Standard coils are pretty good but I'd go Mopar if it were up to me.

If some of the coils are going bad, the others are sure to follow.. replaced all mine after 2 were going bad, and now I tale the ones that were "still good" with me as spares when I know I'll be going through deep water/mud holes... they've come in handy plenty of times and kept me from having to limp my way home on half an engine lol.

As for the crank and cam sensors, only use Mopar replacements.. heard some stories awhile back from a buddy who replaced his cam sensor with an aftermarket one and it actually ended up hitting against a cam lobe IIRC..

GunnerSchenck said:

If some of the coils are going bad, the others are sure to follow.. replaced all mine after 2 were going bad, and now I tale the ones that were "still good" with me as spares when I know I'll be going through deep water/mud holes... they've come in handy plenty of times and kept me from having to limp my way home on half an engine lol.

As for the crank and cam sensors, only use Mopar replacements.. heard some stories awhile back from a buddy who replaced his cam sensor with an aftermarket one and it actually ended up hitting against a cam lobe IIRC..

Click to expand...

That's exactly what happened to me. A DEALER in Memphis used a NAPA sensor cuz they were out of stock on crank sensors; they said it carried the same dealer warranty as a Mopar unit. What good does that do me when I live in OHIO...?

Anyway, I replaced the NAPA part with a Mopar. Here's what the damaged NAPA sensor looked like:

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Bob

Ooouch. At least you caught it before you ended up with a flat spot on one of the lobes.. I don't think the warranty would've covered that lol

ltd02 said:

Did you use Mopar crank and cam sensors? If the coils were original it may be a good idea to swap them and see. The old ones don't owe you anything after 188k. I've heard the Standard coils are pretty good but I'd go Mopar if it were up to me.

Click to expand...

Running 2 mopar coils, 2 duralast coils, and 2 valucraft coils. Gotta say, can't tell any difference myself between the brands, but... that's not to say my engine can't tell the difference lol

Your p0306 code you had that cleared itself, could've been that one of the coils didn't seat itself around the plug and after a couple or sparks from starting/restarting and then letting it sit, perhaps then the coil tightened itself down to the plug from the heat created during the sparks...

Or not, but just my guess

ltd02 said:

Did you use the recommended copper core plugs?

Click to expand...

How about it, OP?

GunnerSchenck said:

Running 2 mopar coils, 2 duralast coils, and 2 valucraft coils. Gotta say, can't tell any difference myself between the brands, but... that's not to say my engine can't tell the difference lol

Your p0306 code you had that cleared itself, could've been that one of the coils didn't seat itself around the plug and after a couple or sparks from starting/restarting and then letting it sit, perhaps then the coil tightened itself down to the plug from the heat created during the sparks...

Or not, but just my guess

Click to expand...

Maybe you don't notice the difference but your motor may.
Can you tell that two are firing better than the other 4 at 70 MPH ?

tommudd said:

Maybe you don't notice the difference but your motor may.
Can you tell that two are firing better than the other 4 at 70 MPH ?

Click to expand...

Lol that's pretty much exactly what I said Tom...
Lol of course I can't tell...but my engine may.
Is it more noticeable at 70mph? I started off with 6 Mopar coils, flooded two on two separate occassions.. keep killing the back 2.
I realize that letting them dry, sometimes they'll continue to work well, but mine ended up with a lot of gunk and burnt sand/junk around them.
Just bought the replacement ones AZ had in stock (just to last me till I got new ones) and never bothered switching them after as they seem to work just fine..

Should I be able to tell that 4 aren't working as well?