I've been working on my 98 Ram, what a pain, the engine is tucked so far back under the wiper cowl you can't even see the distributor, let alone get to it, I have a miss at idle and an occasional back fire out the tail pipe, it's been parked for a couple years after mice had a field day with injector wires and vac line, but it ran fine when parked.

191,000 miles
Since recently working on it, I've:
Drained the old gas.
Rewired new injector plugs, installed new vac lines.
Replaced the PCM, only code was P0206 with the old PCM, code free with the new PCM, I wore out my multimeter and noid liight checking everything.
Firecore plug wires. Hence the distributor rant.
New plugs.
Original coil and coil wire.
New IAC, cleaned the other sensors and TB.
It has a gutted cat and a blown plenum gasket.
I'm planning on doing the timing chain and fixing the plenum in a few weeks, hence this post.can I use RTV instead of a gasket on the plenum?
I get the aluminum plate, but I'll probably only have the truck a couple years more, FYI I tossed the Keggar along with the PCM that was on my Dakota in the dump.
Any ideas on the miss?

I'm pulling the front off so I can stand in the engine bay to do the plenum plate/timing chain, It's hard to believe the same size engine is harder to get to in the larger Ram than on a Dakota.
Picture of the 410 in my Race Dakota. Easy Peasy to work on.

 

If you remove the fan, and fan shroud, there is a lot of room to work in the engine bay.

I put a board from the radiator support, to the throttle body, (covered....) to lay on when working on the distributor. Yeah, access back there was a really poor design choice.

Beg/borrow/rent some noid lights. Test and see if the current PCM is even attempting to control the number 6 injector.

 

Checked it right after I hooked up the new PCM. Worked fine, I'm the proud owner of a noid light.

 

Still getting the code? Might try swapping 6 and 8 injectors, see if the problem follows the injector.

 

Sorry, no codes after replacing the PCM, I'll edit my post.
I haven't driven it yet, maybe I should.

 

Always have to test drive to see if the problem is indeed fixed. I've been burned by assumptions way too many times...

 

Checked my fuel pressure, 50 psi. Pulled the gauge off, started it back up, it runs great now. Huh?
My ABS and brake warning lights are even off, they have been on for years. Double Huh?

 

Your elves finally got their act together, and DID something. Mine only seem to break more stuff.

 

I'll take it for a spin today. Fingers crossed.
I wonder if there was still bad gas in the fuel line, I pumped it all out using the schrader valve, but some had to be left in the fuel lines, all I've done is idle it but I did add new gas and keep pumping out fuel. Who knows? Stupid sensors, that's why I ditched all the JTEC crap on my Dakota.