Was wonder what the differnce between a 4-1 header and a 4-2-1 header? Do they give different performances at different speed? Aslo i was planning to get a Catalytic Converter but i cant seem to find any for my cavalier 03. I did find this though http://rksport.com/product/p_020994005/view_detail but it says it doesn fit on an Ecotec Engine.

I think, THINK, 4-1 headers give you best top end performance while 4-2-1 help retain your low speed torque. Someone will post soon and confirm this or correct me, I'm sure. It's still early in the A.M. :tongue:

that is correct 4-2-1 header is better for everyday driving it makes it a little more fun. 4-1 header is better for drag racing it makes better top end power. 4-2-1 gives a broader power band while 4-1 give a more narrow power band.

Try rsmracing.com they have great stuff for j-bodies. When i had my 2.4L that is where i got all my stuff.

4-2-1 is better for high end, undesputable truth.

eh I Was wondering the same thing myself. now I know. thanks guys