Weird Missing Issue

Tonight when I replaced the o2 and went for a test drive, I got 50 feet down the street and made a turn onto a slightly uphill road, and it went to missing and acting up something awful, to the point where i thought the motor had died, but again, i just floored it, and it cleared up and ran OK from there.

This is the o2, it's original to the truck w/ 316k miles

I'm going to say that you quite possibly have a vacuum leak somewhere.

Time for the "Rubber glove and blow smoke into it" trick *grins*

RwP

Yeah but that's the thing, i don't hear any hissing or anything to suggest a vacuum leak.

I've tried to get video of it, but the iphone doesn't pick it up, and my damn digital camera is mostly hissing and static.

Unfortunately it could be anything, there's lots of ground to cover with a miss. If you're not getting any Engine Codes that indicates that the fuel system is probably behaving correctly, or very close to correctly. It could be ignition but if you've replaced plugs, wires, rotor & cap then all that's left is the distributor itself. Don't count it out.....

Could be rings or oil fouling in a cylinder. I hate chasing this. Its easier now that these micro cameras are available - you should be able to rent something for a day to snoop around in the cylinders. I'm not sure I'd start there though.

Could be a vac leak, maybe not outside the engine but inside. Possibly intake to head gasket leak into oil gallery. Also do a search for the intake belly pan gasket failure. These tend to go without warning and could cause a miss but I haven't seen that identified as a symptom.

Could also be a rusted out intake hold down bolt. or 2. When I removed my intake a few years ago more than 1/2 dozen of the intake bolts snapped while trying to remove them. A few had no tension at all & only the top inch or so of the bolt came out just by lifting up the head, no wrench required. The rest of the bolt remained safe & sound in the head. The head is iron & the intake is aluminum and the bolts simply corrode away to dust from electrolysis, its just a matter of when. If that has happened you'll definitely get a leak.

If you check intake bolts make sure you can find replacements BEFORE messing with them. If any are dead or snap on you'll you'll have to replace them. They were dealer only parts when I snagged some. I doubt they are still in Dodge's parts inventory now so you'll need identical replacements. They may be hard to come by, proceed with caution.

Last thought is fuel pump. If you're not getting enough fuel pressure it could present as a miss. Usually the truck just quits completely and after it sits long enough for the pump to cool down it will run again for a little while. It can also present as a truck that won't start. Try a fuel pressure test. You can get a fuel pressure gauge for $20 or $30 bucks & its a quick test.

Good Luck

Turns out my CEL bulb is blown, and it did in fact throw some codes..

Got a 1391 and a 0302, miss on cyl 2, and intermittent loss of signal from cam or crank sensor. But the 0302 is caused by the 1391.

New sensors are on the way.

Same problem here for a few years. Replaced all ^ and plenum fix [which I could have f'd up]. Been too busy/lazy to do, but I'm leaning towards vac leak, timing chain or dist. A lot of others here have the same problem but I haven't come across any post that has the cure. 'Cept maybe sellin it.

Well the new sensors came, and sure enough, absolutely no improvement.

The plenum gasket was replaced a few yrs ago, and the last time i checked down in there, it was dry, maybe misty, but by no means a huge leaking puddle.

It occasionally will go full retard, like at a stop, it'll start missing and shit, barely running, and I'll have to put a foot on the brake and gas, and basically floor it, like you're gonna do a power brake burn out, hold it for a few seconds and it finally clears up and runs right..

WTF is going on with this truck?