I've said it before, and I'll say it again.
It's not 1975 any more.
In 1975, auto makers needed to comply with new stricter regulations, so they added some bolt on filtering to their 1974 models. Not surprisingly, there was less power.
So you could increase power by removing some factory parts and kind of retroactively turning your car into a 1974 model.
Now, that was 30 years ago, and automotive engineers have been working with emissions controls laws as a design constraint since before most of them came out of college.
So modern cars are designed to optimize across a set of criteria that includes
The entire design from end to end is working with that in mind.
So, how do you make your car more powerful than it came from the factory?
Well, one way would be to go down to your local performance shop, where they've got a dynamometer, a machine shop, and a handful of dudes who know their shit, and you say to them: "Here's $20,000. Build up my ride. Make it run fast. It doesn't need to pass any emissions tests when you're done."
You'll probably come out with a stoked engine, low restriction inputs and outputs, a blower, a requirement to run premium gas, and custom electronics tuned to the new configuration.
But if you just get out your toolbox and start randomly unbolting shit, like you would have in 1975, it's more than a coin toss you're gonna end up hurting performance more than helping it.