Q: Low idle and runs rough, plenty power, replaced egr,tps,iac fuel pump and filter on 1997 Chevrolet Suburban 1500

Rookie cbe0621eac06868b3efe0d8d1d3611e23c60d3114864ea2ec19a68cfbd3eebab
Replaced distributor, updated injectors, replaced o2 censors, runs much better but still idles at around 500 rpm and runs real rough. Also has a slight backfire when idling.
(1) Answer
(1) Comments
Scope ignition, smoke test for vacuum leak, pay cloose attention to intake gaskets. Can use carb. spray but have fire
extinguisher handy! INTAKE and plenum. Intake gasket vacuum leak can cause intake backfire. Is it exhaust backfire?
Is CEL on? Any trouble codes?
It sounds like exhaust backfire and it sounds like lil pops in the cat. Could it be a clogged cat? I drove it today about 100 miles on highway and it runs smooth at 2000 rpms but slight struggle to accelerate. When I slow down off of highway it idles real,low and shut off once on me. It is giving a po300 random misfire code and the code for an o2 censor , could it be the knock sensor throwing the comp? It doesn't give me a code for the knock sensor though.