knock sensor
I have a 92 s10 blazer and my code 43 was fixed by replacing the knock sensor. so maybe check the knock sensor and the wiring from that to the ECM.
any from 88 to 98
knock sensor
probably the ignition switch if you are refering to the starter solenoid.
Owners manual, positive.
ESC / Electronic Spark Controll Circuit. and the knock sensor signal.
no you need the catalytic converter replaced or removed but the o2 has a code of its own which it is P0141 and says the sensor is malfunctioning
System Normal
it might be a broken motor mount. there are two mounts located towards the bottom of the left and right side of the engine make sure you are getting spark to all cylinders. (check for Misfiring)
There is 2 on that engine and both of them are screwed into the exhaust pipes up close were they bolt to the engine. They will be about 3 to 4 inches long with an elctric wire coming from them.
My 94 blazer had this problem and it was the fuel pump. My Blazer eould start and run for a few seconds and the die,after Ichanged the fuel pump it started reigt up. . Awhile back my truck wasnt staying started for more then five seconds, and it turned out that it needed the RPMs adjusted bc it wasnt high enough to keep the truck going =( didnt cost much though