Hey guys, had my first check engine light up in a while and it's a new one to me.

I drove to work this morning and ran as usual (not perfect, not complaining) and soon as I started it up this afternoon the check engine light comes on and I notice it idles a little rougher than usual... no stalling and put the foot to it from a stop and it goes fine.
I put my code reader on when home and it gives a P0306 as in my title.

I looked up some threads here and found this one https://dodgeforum.com/forum/dodge-r...0306-code.html

and went with Blackvan's advice to inspect and change out the distributor cap and rotor for starters. I also pulled #6 plug and #8 to take a look since they're neighbors and see they are actually wearing pretty normal but time to change them out after about 25k or so on them I think. Bought new NGK coppers to replace sometime this week.
The distributor cap also didn't look to be anything but normal wear. I'll add photos if asked.

I changed out the above mentioned and now there are a P0300-P0306 and P0308 codes but seems to idle the same alittle rough but not way bad. just a note ** I did notice a slight smell of fuel with engine running at this point while by the engine but not sure of the source,
Bad fuel injector??? IDK

Also checked out troubleshootmyvehicle.com to read more on misfires since I'm not so keen on where to begin as I've never dealt with misfires. I'm seeing that there are a few things that could be the problem... including the plenum job I've been procrastinating on doing.

Just looking to get a thread going on this and for some help/ suggestions to resolve the issue

 

What are the vehicle specifics, year, make, model, engine...

 

1999 3500 ext. cargo 5.9 forgot this info doesn't show up anymore.

 

When stomping on the gas makes the misfire go away it is usually due to a sticking fuel injector. An ignition misfire gets worse when stomping on the gas because the density in the cylinder goes up which makes firing a spark even harder. But with an injector the PCM tells it to open wide which gets enough fuel into the cylinder to make the misfire un-noticeable or non-existent.

 

Thanks for that reply alloro, turns out it was much simpler this time (in my case) than would have expected, and glad for a cheap fix.

Fired it up this morning with the intention of taking it 5 miles to the home I'm working in, hoped it would resolve itself over night. Got half a block and the CE light started flashing so parked it and took the pickup today.
Talked to my boss who is a fair mechanic and explained what codes and what i had done so far and he offered to help and bring along his compression tester later today.

I got off earlier than usual and began looking up more on misfires, read and viewed some videos but happened on one youtube video where a guy had thrown some parts at his 2002 truck, same codes but with no success, and later posted a second video telling what he had done to fix it... he replaced the spark plug in his problem cylinder (#6)
I had bought replacement plugs yesterday, planning to go ahead and replace them anyway so gave it a try.

I rechecked my plugwire routing on the distributor to make sure I didn't goof the firing order on the new cap and sure enough crossed one with another! Fired it up and still no good so pulled the 2 plugs throwing codes (on 6 and 8).

Still thinking to myself, why would these would be a problem, they just don't look all that bad... I checked the gaps put the 2 new ones in, leaving the metal sleeves off and cleared the codes, then disconnected the neg. battery for a few minutes.
Turned the key to on for 20 or so seconds, shut off then fired it up...
no CE light and also checked for codes noticing idle was much better. Took it for a road test and so far looking good, so far... guess I'll get those other 6 plugs replaced by the weekend too.

 

Just a quick update to say the van ran fine today and guess I should write the fix down because in 20-25k more miles, it's doubtful I'll remember what I did to resolve a misfire code.

 

Last update for this... changed the remainder of the plugs today after church and only found that the number 2 plug was fouled worse than #8, the rest of the plugs by comparison were much better but all in all this was my "sign" and I guess it was due for the tune up.