I know this is the Ford Trucks site, but i have a 4.6 Mustang question, and I trust the people here more fot advice. I usually rat around in the 351/400 and 72-79 F150 message boards.

The vehicle is a 99 Mustang GT.
It is a friends car who has the money to do almost anything but the $3000 supercharger at the moment.

I am looking into:

1) the X pipe exhaust with 1 cat per side and a set of flowmasters.
2) Removing the airbox and putting a cone filter in its place.
3) Maybe a chip

What i am wondering is how much difference would a larger throttle body and 1 size larger injectors do for this engine with the other mods in place. How much can the stock computer take before it starts throwing codes out.

This will be my first computer controlled vehicle mod so I am being safe and asking first.

I much rather a Holley and MSD box being the most technologically advanced parts on my engines.