need feedback:
truck- 1997 4.2 xlt manual supercrew with 245000 miles, rebuilt top end, one new cat, all stock except for air filter

symptom-truck rpm fluctuating (up to 500 rpm at itimes) or driving (foot held at steady rpm as well), dies when at idle frequently....

what I've done- check for codes (none), cleaned maf sensors, checked for vacume leaks visually and with carb spray, cleaned/tested IAC, checked connections on egr sensor and the sensor behind it, reset pcm

what I've replaced- fuel filter, plugs, coil pack, pcv valve, several hoses, TPS

I know I have a vac leak as my cabin vents do not blow on face (default to defrost) could this be the culprit?

I am open to suggestions and thanks in advance.

here are a few screenshots of live data.... not quite sure how to interpret. there were no codes stores or otherwise.

 

You do need to fix the vacuum leak, look behind the battery at the small vacuum hardlines and the accumulator.

 

the vent leak has been that way for along time. this current issue only started 2 weeks ago. related??

 

Well, it may have gotten worse to the point that it's upsetting the fuel/air balance? I don't know.

It's quite possible your EGR valve is sticking partially open, that will kill the idle.