my 98 dodge ram is running rough it is hard to start and when i am driving and slow down it trys to die and it seemss to be running alittle rich. i cant figure out what is causing this

 

Yo,

there's a variety of reasons for this you'll find mentioned in the forums.

My truck (same as yours) had similar issues. Replaced my pre-cat O2 sensor and it cleared right up.

A tune up (caps, rotor, plugs, wires) might be in order too.

A clogged cat might not be helping things.

And then there's always the intake plenum....see here:
https://dodgeforum.com/forum/2nd-gen...um-thread.html

 

i kinda think it might be a clogged cat cause it was running fine then i got in some mud and some mudy water got in the exhaust

 

just a heads up about the clogged cat. mine too was clogged (due to probably bad plenum) so i went to a y-pipe with no cat (no emissions here in SC), but my truck is still sluggish. im in the process of collecting all the parts for a plenum replacement.

from what i've read and been told check the plenum first before you replace the o2 or cat. if not you're gonna be back to square one if in fact the plenum is jacked up

 

ok thanks how do you check to see the plenum is messed up

 

check out the link in post #2.

 

ok ill check that first

 

I have a 2000 Dodge Dakota 3.9 when the outside air temp is hot the truck misfires and runs rough, when outside temp is cool like at night, it runs fine any suggestions is appreciated.

 

IAT sensor perhaps?

 

Cross posting in different sections with different trucks with the same issues: https://dodgeforum.com/forum/1st-gen...u-problem.html