I'll give that a shot and let y'all know how it goes, thanks

They will eventually throw a code but not until long after you've torn out your hair trying to figure out the problem. Happens that way all the time.

Unplugged it and now it only runs bad for 20 seconds and then purrs like a kitten, looks like I'll change it out and just deal with a 20 second rough idle, I've heard our trucks don't like bosh sensors is that true or just the dealerships way of making us buy mopar ?

It's true. Get a Mopar part, or NTK.

if unplugging it helped, for sure replace it, NTK is good, check rockauto for them. if the sensor is bad, i would wonder about the cat being clogged a little. is the plenum gasket good or is it leaking? check inside the intake manifold and see if you see oil. if you do then id bet its blown and fixing that along with a full tuneup and i bet your problem is fixed.

Plenum gasket was changed at 92,000 miles (at 104,000 now) I'm not sure about the cat, the truck sit for 5 years before I got it I'm still working kinks out. I'll order an upstream o2 sensor and check that off the list

yup yup. hopefully all will be well with the new sensor.

If worse comes to worse I scored a wrecked 99 ram with a rebuilt 318 I could always do a motor swap.

Swap the trans as well. I think the 3.9 trucks came with the 42 or 44R? trans. (not as strong as the 46.)

42re. I imagine it'd be a pretty straight forward swap since I've got a complete donor truck.