Some 99 Grand Prix vehicles will shift hard when it is warm. Not all of these vehicles will do this.
Yes
fast.
The Charcoal canister for a 99 Grand Prix Gt in in the drivers rear tire well. you have to remove wheel and then a plastic cover to get to it.
R134a
An engine compression test on a 99 Grand Prix GTP can cost $180
In short, yes. Long Answer: Yes they truly are the same.
Yes
The low pressure port on the 99 Grand am is on the passenger side. It is right against the firewall.
It doesn't have one if its an SE.
Yes, as long as they are both 4T65E transmissions they will easily replace each other, everything is the same.
The GP was redesigned in 2004 so parts are only interchangeable with 2004 or later. 99-2003 wont work.