Ok, so now the rest of the story that you haven't actually said anything about:

I see on your profile that you have a GSR engine. Sort of an important detail to omit when looking for help, don't you think? So, you're running that engine with a stock P28? Awesome.

You'll pick up some HP with the correct ECU, because you're using a completely incorrect tune for that engine. So you haven't been very kind to that engine. You should really get a P72 just so it runs safely and nothing else, because the extra power isn't going to be enough to add more than a few more MPH max if you're topping out at 120 now.

And you're still a complete idiot for going that fast on public roads.