Help: upgrading to play GTA?

Hello everyone, I am new to this forum, but not new to using video game forums. Normally I would use the search function to get the answers I need but I have come up with either way to many results, or none at all. I recently bought my psp along with GTA, and had the idea I could play roms as well. Anyways, without knowing, I updated to 2.0 as GTA required to do so, so that I could play it. Later I wanted to put roms on only to discover that I had to degrade the firmware. So now I am pretty happy with all of my roms and everything working (except for the few laggy games that are to slow to play) but I was wondering if I would ever be able to play GTA again. I dont want to have to upgrade again for obvious reason, but I would like to play it. Does anyone know of a patch or something that allows me to bypass the upgrade before playing.
Thanks for the help

PSP v2.0 + GTA + Fanjita's eloader = :D

keep in mind the best homebrew lies within firmware versions 1.0-1.5. But if you truly insists on playing GTA Liber City Stories. Then here is what you do upgrade to firmware 2.0. after that you should be able to play GTA. Also if matters come to where you get sick of the game and you want to have 1.5 firmware again you can downgrade your psp. Also there are even some hacks for 2.0 firmware to play some exsiting homebrew. But it does not support kernal keep that in mind.

Well as it is right now, I have a 1.5 PSP, I was just wondering if I HAD to upgrade to play my GTA because I am pretty happy with all my roms, and from what I understand is that the backdoor in GTA that allows you to play homebrew doesnt support anything like NesterJ.

You do have to upgrade to version 2.0 to play GTA. With 2.0, you don't need GTa to play homebrew, fanjita has a standalone eBoot loader for that.