The ECU will always advance timing with the SPOUT connector plugged in..
Remove the SPOUT connecter, and retard your timing 5°
Then after you do that, reinsert the SPOUT connector and go for a "spirited" drive..
Basically, you want to duplicate the same driving conditions you had before..When you heard the *pinging
Your ECU is advancing the timing too much for the octane of fuel you're using, so compensate..
If for some reason, after you've retarded the timing 5°..You're still getting the *pinging, retard it a few degrees more..
It's imperative, that when you set the timing..The SPOUT connector is removed
I suspect your Harmonic Balancer has slipped on you, and you're running more timing than you think..
Report back, with your findings..
1991 Ford Thunderbird Sport
"If you don't know where you're going..Any road will take you there."
– George Harrison