Took my "new" Regal GS to work the other day and got this pulsation in the engine when I was going up an incline.
At a little under 65, lightly accelerating to go up, it surged a few times and leveled out on top of hill.
Now it's starting to do a little on flat ground at light accel.
Friend who has a Comp G told me plugs. I thought maybe the S/C cuz the coupled needs replaced but throttle wasn't enough to boost.
Just got it a few days ago. Dealer's service report showed new MAP sensor installed. Nothing else done. Oil wasn't even changed (not that it matters).