Car shuts off when trying to accelerate. Both cam shafts & VVT replaced.HELP!!

What is your question?

Has been to Cadillac dealership with new ECM & tunedup. Was fine for 5-600 miles & started rough riding then smoke from under hood. Took to a local repair mechanic & he used diagnostic computer & only 86,000 miles both cam shafts replaced and variable valve timing. Slow test drive no problems encountered but when I had paid another $350, I slowly got to highway entrance & reached media then pressed accelerator, car completely shut off! By now, I have spent $2500 in repairs & tuneup where I had to have spark plugs supposedly melted to boots replaced! Cadillac dealership charged me for new Core, I told my brother & he asked if I had been given mine! I hadn’t & he said it didn’t need replacing! I contacted Svc Mgr & he agreed I had been accidentally charged & was due refund! I can’t trust them anymore as several questionable charges on invoices which started with a $700 charge with no explanation! The mechanic that has my car can’t seem to locate problem. Please call 863 449 1442!

What makes this problem better or worse?

It has had $2500 repairs & now shuts off when accelerating!

How long has your 2006 Cadillac STS had this problem?

5 days