0411 swapped my 2000 Jimmy/Blazer using 01 4.3 tune and it runs very well although at random times the aspark goes directly from 100% to 0% "no knock at that instant" and doesn't go up to 100% until a reflash. I've even set B6220 "Octane Scalar Modifier" to enabled and B6221 "Engine Run Octane Modifier" to 1 thinking on a restart it should reset aspark back to 100% but it stays stuck at 0%. What the he|l is the PCM doing here?
