I own a 1990 Legacy LS sedan and I had a question for everyone. I would like to change my stock pan style air filter, with resenator(sp) box, to a performance cone style filter. My question is that when i took the resenator box off, there was the mesh screen on the hose right infront of the air sensor unit. Would i have to cut off that mesh screen inorder to put on an aftermarket cone style filter, and if i do, would i have to have the ecu tweaked? Any help would be great thanks. My email address is hijirihazo@aol.com if u want to email me.

Nevermind, I found out I needed an adapter, I dont have to cut the screen. But i still need to know if anyone knows if Ill have to modify my ECU because of the increased amount of air coming in?

you shouldn't need to modify the ECU unless you go forced induction. I would however unhook the battery, pump the brakes (gets free electricity out of the system), and reconnect the battery after a few minutes. This will clear the ECU's memory, and upon the next drive, it will relearn your driving habits and adjust to the extra air. Good luck.