Could this be a Throttle position sensor problem?
Or something else. on 2001 Chevrolet Blazer

idles rough, RPM fluctating , vehicle has stalled at stoplight but restarts right away.

Asked by for the 2001 Chevrolet Blazer
it could be many things. but you can start by replacing fuel filter if over 2 yrs since last filter changed. need to check fuel pressure and check fuel pump.
1 more answer
Check the EGR valve. I've seen carbon keep the valve open causing rough/surging idle and stalling