At 155k it wouldn't be a bad Idea to replace the up stream o2 sensors. But on most hot soak issues on the 4.0 liters its the injectors getting hot.
Do you still have the tinfoil fiber thing on your intake manifold?
And we have fixed a few Jeeps with your problem having the Injectors tested...
Its not to hard but you need to be kinda precise when drilling the holes and taping it... and you have to take the box apart....
I don't know where you are located but if you bring the box in we can do it for you at Auburn Car Repair and Offroad. Hit up John (Avanteone) for a quote..
Shake down the front end... Ball joints are a common problem could be a tie rod or your steering box could be bad.....
Or take it over to Crashes house and have him look at it....
I'm going to say you have a wheel issue... Are you running Steel or Aluminum wheels.. My boss Avanteone is running 37" mtrs on aluminum trailreadys with no balancing and it drives smooth at 70mph... and it was the same when he was running the Racelines... If you are running cheapo steel wheels...
Hey crash
This is jason I work for John at auburn car repair..
So john blew his headgaskets on the duramax so I get to do them.. YA
I was reading on the duramax forums and if you do ARP studs you should pull the body is this right and how hard is it. Any help you could give me or time savers...
I've got the HID-X in the 4" flavor and I love them. Very bright for a $100 light. John (avanteone) has been running them for like 2 year now and they still work awesome... Here's a pic of them on...
One I never loan my trailer out anymore.. There is always something f*cked up when it comes back...
Two once a year I pull all the wheels and check bearings and adjust brakes..
Pull the MAF and look at the the little wires and see if they are dirty if so then clean them with some carb clean but be careful they are kinda fragile.
Dirty MAF sensor is a big issue with Furds....