So I had thought after last fix, I won't be posting regarding same issue. But that is not so. :-(
Evey other day mostly close to 24 hrs after reset, check engine light comes on again. Code on scanner, MIL/FTC/Perm/Present is P0455 Large leak detected.
I reset it, and wait for it to reappear the next day. Sometimes 2 days. And now every 4 to 5 days, P4096 Small leak detected. When the small leak detects, the large leak code don't appear.
So far, I have replaced, throttle body with new BOSCH unit, purge valve solenoid with new ACDelco unit, and Charcoal canister solenoid and new wiring harness with ACDelco genuine parts.
Cadillac of Ann Arbor MI ran a smoke test and found no leaks.
Thanks again in advance for all your help.
Engine 3.0 liter v6 Performance Edition AWD.