I was thinking of removing the air silencer out of the stock intake box for a few free HP and slightly better MPG, and also better sound. Any thoughts on this? If i do this, will i need to get my ECU reflashed? How do you reflash an ECU anyway, with a scanner tool?

 

Only expect the extra noise, you won't notice anything else. No you don't have to retune.

 

^ +1
Its actually possible to lose some power
A true test would be dyno

 

I did it. No difference in noise or power.