acceleration problems

Hello, my name is Nick and I have a 2003 Buick century I recently bought with around 190k miles. When I purchased it, the only key they had was the (I assume) valet key, considering it only works to start the car, not on any locks. However, the car can reach speeds of 50mph and as far as I know...

I have had an issue with as long as I've owned my Riviera, whenever I go to accelerate onto the highway or from a relatively low speed to a higher speed, it seems like my engine bogs down. If I floor it, my engine revs up but it seems to lose speed instead of gaining it. And if i let back off...

Sometimes when I go for a drive, there's a slight resistance and groan as I press the pedal to accelerate. It might be my leaky power steering still giving me trouble even though I've gotten it "repaired and replaced" a few months back. I used the quotes because I've taken it back to the shop...

I pulled off the Throttle body first to clean and inspect it. Upon removal it was apparent that there was serious gum-up in the upper and lower intake manifold. Removed, cleaned and reinstalled the upper and lower intake manifold and the Throttle body. Issue persisted with no change. Replaced...