Hey guys! I just joined this forum hoping you guys would know how to help me. I modded my SI by adding cold air intake, exhaust, new spark plugs (Bosch platinum), plug wires (10mm), Headers (Stainless, 4-1). I did all of this hoping that it would add some power to the car, and it has but, I find that at certain RPM ranges it lost power. After speaking with a few of my budies they say that I should have upgraded my ECU EPROM chip as well. My questions are: 1) Is there an upgrade? 2) If there is, where can I get one? 3) Brands? 4) Will it help? Im just hope I haven't messed any thing up or screwed my car up. Also after installing the cold air intake I notice a chirping sound at certain RPM ranges as well. I'm thinking it might be the intake but I dont know. If you guys can help me it would be greatly appreciated. I'm kinda a noob at some of these issues, so any help/suggestions would greatly help. Thanks!