Truck stalls when warm on hill

I have a 96 Dodge Rm 1500 pick up, 318 cu in fuel injected. 24000 original miles.
A problem has just popped up. Vehicle runs very well and as it warms up it will shudder, check engine light comes on, and vehicle will lose power. You can hear a faint popping sound coming from the tail pipe area. The vehicle does not stall it crawls and sputters and then stops. I let it sit start it up, runs lousy and then goes back to crawling and not moving at all. This usually starts after 10 miles.
The loss of power occurs on flat areas and coming down a hill. It always happens after the vehicle is warm.
Any help will be appreciated because I live in a rural area and had the truck towed three times. I never had any problem before with engine performance. Only thing replaced prior to this was the electric window opener, which causes the window to hang inside the door. After playing with the switches it will go up. I do not think this is related to the engine performance.
Thank you for your help. Dennis