Is it ?? ..... the engine "stumbles" ?
Engine oil pressure is used by solenoids
to activate the variable valve timing
of valves opening and closing on the combustion chamber.
It could be the solenoid
that controls the VVT variable valve timing, has filter screens ( on the solenoid)
that are plugged with engine oil gunk.
When you step on it, and vvt solenoids are electrically energized,
The engine oil, and subsequent oil pressure,
is SLOW in flowing thru the plugged screen cloth on solenoid
And engine oil pressure is not able to activate the solenoid, the solenoid which advances engine timing,
fast enough..... hence a stumble.
There is a recent post on traverse forum, called
"Traverse Stumbles on light acceleration No Codes"
where a brilliant "testbob" disassembled
Then cleaned the filter screens on the 2 solenoids....
( one solenoid controls the intake valves, the other solenoids controls the exhaust valves)
He actually has 2 separate posts on the same topic, look for them, read his comment and his solution,
he fixed his problem.
Here is One post
His 2nd post is a detailed summary of his findings.
Is That ^^ root cause.... WHO KNOWS??