^^ YES< you CAN use a PC5 with a flash but "how" is not so simple. If the fueling is already changed from stock and you want to try different fueling, you can't just throw in another map. You have to use AutoTune to change your fueling safely or else get a dyno tune /reflash.
I'm not dissing flashing. I just have never quite been convinced it is better than modules for all the things modules can do....and modules are made so you can change the mapping to your hearts content where flashing is do or die. Even a lot of flashers recommend a PC5 with their flash. For a Gen1, I honestly don't see a real advantage to using a flash unless you don't want to mess with all the work of installing and learning to self tune. I'd have to try it but so far, what I know about how mapping works, a flash is just a less expensive and quicker way to do it without needing to do any work installing. That is a very nice package for a lot of owners but it's a step away from perfect unless you have the same mods that the flash was created with. All these years people have been looking for a map to match there exact pipe and now that everyone is flashing, nobody cares what full system the map was created with?? If you ever want to go with a turbo or NOS, you darned well better know what the timing was flashed to or have that put back to stock so you can take care of timing yourself.
'08 MIDNIGHT SAPPHIRE BLUE Now Deceased