97 Ram idles rough after long driving.

I have a 1997 Dodge Ram 4x4 5.9(gas). I'm having problems with hesitation on take off and if I drive it long distances it begins to idle very rough and black smoke pours from the tailpipes. I have replaced the TPS,MAP,IAC sensors. Also changed plugs, wires, cap, button, and had an upper intake flush. Has anyone else had this problem? Does anyone know what my problem is? Any help is greatly appreciated. I'm pulling my hair out over this. Thanks.

Catalytic converter plugging or plugged.

My catalytic converter has been gutted out. It's been that way for a couple of years w/no problems.

I took it to my local autozone for a checkup with their handheld. They said I had a bad speed sensor. Does anyone know if a speed sensor will cause my symptoms of hesitation and rough idle after the long trips?

Might be your oxygen sensors?

Well I broke down and took my Ram to local Dodge dealer garage and they told me I had a bad fuel pump. Although I haven't taken it on any long trips since I put in the new fuel pump, the hesitation issue seems to be resolved. When I stomp the pedal I get instant response. So I'll cross my fingers and hope the $400.00 pump fixed my issue.

Did your check engine light ever come on?

http://www.allpar.com/fix/80s-codes.html

No my check engine light never came on. I don't think there's a bulb in there or it's just burnt out. I've had the truck a couple of years and have never seen a check engine light. I guess I need to check. The previous owner probably removed it. I got a repair manual for the Ram and had tried that self diagnostic thing, but with no light it won't help out. But as I said the Hesitation issue is definitely resolved. I'm happy with that. More than likely the rough idling and smoking was an overfeed of fuel since they have the pressure regulator built into the fuel pump module itself. Thanks for your help.