I remember reading about a fuel injector upgrade that allows a little more power and cleaner combustion. Can anyone point me in the right direction on the injectors needed?

 

You can run RDX injectors but unless you're FI there's no benefit.

 

You might have heard about direct injection which is not possible in our cars. It allows a higher compression ratio, more boost, and less octane but it comes with it's own set of problems.

Otherwise port injectors with a supposed "better" spray pattern than stock if there is such a thing would only be worth a fraction of a percent in power and mpg, far from being measurable.

Ford has been testing an ignition system that uses many ignition points in the chamber via lasers vs a single or double spark plug setup but even that is not worth a measurable power or mpg change, only a nearly unmeasurable emissions improvement.

With the EPA and the hundred other government agencies trying to get money from the big manufacturers, the cars are pretty well optimized for best mpg and emissions off the showroom floor. I'll guarantee the 11:1 compression and the premium fuel requirement was to help out mpg in the heavier and larger engine'd TL vs Accord.