Since i'm the first to read i'll flame you first before the others. USE THE SEARCH BUTTON. There are already topics on this and the answer to your question is there. But since i'm nice i'll give the that answer. The TRD exaust probly gives up to 3 hp and you wont even notice it. It is for sound and not really a performance. Most exaust on NA car would not give much hp, but if you have FI it sure will give some more hp.