ping ping can't find the problem

Newbe here and in need of help.
92/full size 5.7 tbi
stage 2 chip
KN filter
new 3in pipes
high flow muffler.
The motor pings under load.
Scan test no faulty codes (3 times)
Timing checked re-checked.
high oct gas or booster always
recent tune
Just had it smogged.
cat was toast/ replaced and passed.
ran better for for 50-100miles.
power loss and ping still and I can smell the new cat
I am out of ideas. ???????????

I'm going to guess look for a lean mix indicated by the exhaust problems and pinging.