I bought a parts truck the same year as mine (1999 dodge ram 1500 5.9 v8 4x4) only difference is that its 2wd. I was pulling some parts and noticed a part that I don’t have in my truck. Unsure of what it is or if I need it in my truck. It’s located front right passenger side.
my question is what is It and do I need it.

 

That's the leak detection pump for the EVAP system. No idea why it is not present on your truck, if you don't have a CEL for EVAP then I guess it wasn't there from new.

 

I've owned 2 1997 Dodge Rams and neither had that either.

 

I was just wonder if maybe someone did a delete on mine cause I have the electric connection for it

 

97 didn't have LDP yet, the 98 FSM states "The leak detection pump (LDP) is used only with certain emission packages." WAG is it might only be present on California emissions vehicles.

 

what would happen if I added it to my truck

 

Why bother? It produces a small amount of pressure in the gas tank then it monitors it to see if there is a leak. If there is you get a cel. I would imagine the pcm would have to be updated for it also. I would think there is more you don't see under the truck since the ones without it are different.

 

I do believe, that while that's the evap valve, you're gonna discover that you need it for the factory system to work correctly. It uses engine vacuum to suck out the gas fumes from the tank as you drive along. In fact, you can hear it click under normal engine operation. If not for the valve being hooked up to the gas tasnk, the tank would swell and begin to leak, for the want of the pressurized tank looking to relieve the pressure.

 

In fact, just to the right of your drawn circle. That looks like the evap valve.