I am trying to troubleshoot my truck. 91 5.2 LA automatic.

I was towing a trailer loaded with potatoes to market on Friday, and about half way there it started acting funny. It idles good, but as soon as you try to pull out it spits sputters and tries to die, but if you're real gentle with the throttle you can get it going. Acted the same way on the ride home with an empty trailer, and then later with no trailer at all. I had it doing 55 on the highway with OD off, but if you laid into the throttle it would just growl at you and act like it was in neutral, though would be fine if you backed off the throttle. It finally gave up the goose about a mile from my house, and I had to pull the air cleaner assembly off to get it to run at all. Got home, left it sit, and it started back up and idles decent, but acts up when you try and drive it. The warmer it gets the worse it gets. When you shut it off and hold the throttle open, it smokes/steams out of the throttle body

Checked codes and it Gave me a 41, 15, and 17. Any advice on fixing these? My haynes manual says the vehicle speed sensor is 92 and newer equipment. I really don't wanna fix things that aren't broken but I need to try and have it fixed by tomorrow. Any advice?

 

In the FAQ in this section we have the list of codes.
https://dodgeforum.com/forum/1st-gen...-96-codes.html
41** Generator field not switching properly
15** No vehicle speed sensor signal
17* Closed loop temp not reached or engine cold too long

Assuming you read the codes correctly you would have gotten code 55 as the last code.

Assuming the codes are correct the code 17 would be where you start, the engine temp sensor is faulty or a bad thermostat.

Code 15, the speed sensor would be used for controlling the OD and TCC and cruise control so if it is faulty these will not work.

Last is code 41, the alternator is failing.

First double check your codes, the link in at the top shows how to read them.
Next reset you PCM by disconnecting the battery for a min. Then drive it around for it to relearn and reread the codes once it has fully warmed up.

 

OK I put a new cat in it today, new distributor cap n rotor, checked fuel flow and condition, and replaced the VSS. It runs much better, but I still have the code 41 and it still stumbles and has issues under hard acceleration, which seem to get worse the more it warms up, and I have notice that it appears my throttle body gasket is leaking at the intake, and it still smokes out the throttle body after you shut the motor off and open the butterflies. I am running out of ideas