Their is air injection tubes on my headers and to what I understand all they do is reduce exhuast fumes when starting the car and take up space. I wanted to know if I remove them and cover the inlets on the headers with block-off plates would it have any negative effects?

 

It wouldn't have any negative effects, except probably throw an emissions code. On the other hand, once the car gets warmed up, there are not positive effects either, so why bother?