Several of you have tried to help me out and I am very appreciative.
I bit the bullet and took my car into the dealer.
Told them everything that I observed.
While I am sure there is an issue with a low intake manifold vacuum, they said everything was in spec and fine. No timing issue, no exhaust backup, and no problems with the fuel pumps.
However...... I was 2 quarts low on oil. There was just 1,000 miles on my Pennzoil ultra platinum.
Started the oil consumption test today.
They also told me that there were 5 updates for transmission control module.
My Lord, the previous owners didn't take care of this car.
$80 diagnosis fee
$80 TCM update
$50 oil change.
At least I know what the issue is and as long as it fails the test, GM will be rebuilding my engine
I will be taking all the stuff I was going to use to clean the pistons and the intake valves back to the store.
I'm sure the cat has been badly damaged and I hope it goes before 80,000 miles.