Ok, I just bought my 04 Monte Carlo ss intimidator 4 days ago. Today I experienced something different. As I'm driving about 35 mph, I can feel the car Hekkup or choke in a way. The car intends to shake or lag while I'm steady on the gas. I never felt this before. I'm not sure what that is. Is that normal? Can anyone please tell me what that is and how to go about this.

Also, while in park, for about 5 min, I'm looking at my psi boost gauge and it seems to be idling? Just a little. Not sure if anythings wrong. But 10 min later it stops idling and looks normal again. The idle is not that big in movement but noticed it up close. Please someone tell me it's ok. I love my Monte.