Code 43 doesn’t necessarilly indicate a faulty knock sensor. That code indicates that there is a problem with the electronic spark control system. More often than not the ignition control module was the failing part that caused that code for me but it is a difficult code to diagnose whithout some expensive equipment and a diagnostic chart.
It would be worthwhile to carefully inspect the wiring/connections at all the components and the knock sensors can fail but they usually don’t usually cause erratic running when they fail. Check the fuel pump pressure and if it is 45+psi it isn’t the problem. Next pull the distributor cap and inspect the cap and rotor for indications of spark flashing through the rotor to the module and pickup coil which is usually caused by old plug wires. If the cap and rotor look suspect replace them and the wires and also the distributor.
There is an ESC module under the hood on that car as I recall and it is rarely the cause of a probem unless there is apparent damage from heat or impact.
FWIW I seem to recall that years ago the GM code 43 was termed “code from hell” because it was so difficult to diagnose with any certainty without installing ‘known good parts’ to experiment.
Excuse me @Defcon3, et al. I posted from recollection and obviously I am off a year or two.