I recently had a car with a constant idle stumble/mis

after years of diagnostics, and even a whole new engine (tossed in a built motor)...it still did it.

changed bin's...did everything....

replaced PCM and reflashed with same bin file.... misfire gone. haven't seen it since...old pcm is now in the trash

this is a 2002 with it just now hitting over 100k....diagnose all other things first, but its a possibility