I have a 96 Caddy with the LT1, sometimes the engine almost stalls out when I come to a stop, if I shift it to nuetral it clears out, not real sure whats going on, I checked all my connections and vacumes and found nothing out of the ordinary. any ideas!!!

 

yea 8 times out of 10 its the opti spark.

 

The idle speed is controlled by the IAC motor. The PCM holds the idle higher until it verifies that the vehicle has actually stopped (VSS signal = 0). There is a table of "follower" values that controls idle speed on coast down. Appears you may have a problem with the IAC motor, if it is unable to keep the engine from stalling. Do you have access to a scanner or scan software that would allow you to observe how the PCM is attempting to control the idle using the IAC motor?

 

Had the same problems when my opti went. Another vote for opti.