i have a 1997 dodge ram 1500 sport.. 5.2 4wd

my rpms were fine and steady an about 1k. out of nowhere my truck started running really poorly and when i came to a stop sign the rpms were going up and down between 1000 and 500.. then drop to between 500 and 250 ..
and so on until it stutters and stalls..

i have replaced all 3 throttle body sensors ..
map
tps
and iacv

it seems more stedy now but it idles at 250-500 rpm

should i replace my catalytic converter or fuel pump/filter
should i check for vacuum leaks ? and if so how should i do that ? and what do i look for ?

what should i do ? please help

thanks

 

how does it run, other than idle?

It could very easily be a fouled plug or two, bad cap and rotor or plug wires.

If it feels hesitant while cruising but smooth under acceleration it could be a bad upstream O2.

Fill us in with a few more fine details........could be lots of different things

 

Same symptoms for me were due to a bad pre-cat O2 sensor. Replaced that and it cleared up.