Yeah I recently posted about an identical issue and all we had -- after enough driving -- was a PENDING code for a #3 misfire. Checked that plug wire and there was zero continuity. This was a '98 1500 5.9

I'd keep driving and keep checking pending codes

 

I recently chased a random misfire that kept getting worse. I ended up throwing parts at it to see what it was. I don't like to do that. I knew my distributor was marginal. I had ordered one but kept running the old one. Eventually, it acted like a bad distributor. I replaced it and the problem cleared for a bit then came back. I even rebuilt the TBI and it still got worse. I finally was checking anything and everything to find the issue. I notice some movement out of the corner of my eye. The new distributor was moving up and down. I pushed it down and the engine smoothed out. The clamp was on right and tightened down properly. Watching it, it was folding at the clamp arms..A crack had formed and the clamp had broken. A $7 part caused all the trouble. I've seen two clamps break in my life. This one and one on a race engine that grenaded at speed. I've got new eyes now so maybe I'll see the next issue earlier.

 

Ok so my scanner came in today, 10 flippin codesP0300- random/multi miss, P0301-P0308- cyl 1-8 misfire, P0138- O2 B1,S2, P0711 TFT sensor.
I had done a full tune up 2 mths ago(was have this issue), replaced O2 B1,S1, went to do B1,S2 but it was stripping, finally got a new socket if not got a torch for heat as well as a new set of copper plugs. My project for tomorrow.

 

What plugs are in it now?

Check the wiring at the trans for the temp sensor code. Wires like to pull out, and short together.

 

When I did the tune up I put autolite coppers in, I didn't get a chance to fool with the truck today.
I'll look at the wires for the trans code too. If wires and plug look good replace the sensor?

 

Yeah. Would be nice to see what the sensor was reporting though...