A friend has a 98 Lesabre that we took out and scanned with my LS1M today. He was getting occurrances of part throttle knock, usually around 15-25% throttle. the knock varied from .2 to over 3. Full throttle didn't seem to be too bad, some knock, less than 1 when it happened. The car has less than 50K miles on it. Any ideas? Is this normal? I can post the scans if needed. TIA.