how much more HP do headers, and complete exhaust with intake give you?
I have a 99 tacoma prerunner single cab 4 cyl. I would like a bit more power, but adding cams, supercharger, its out my budget at the moment. So the mod I could do its to change the stock exhaust system, that means headers, magnaflow exhaust, intake. But my question is how much HP would I gain over stock? The HP for a 2.7 engine is 150, right? Also would this save a bit of gas? Thanks!