is the prelude downpipe the same as the accord downpipe? I assume they are not. I mean the H22 prelude

 

What years are you trying to compare? 5th gen H22 has a different length downpipe compared to the 4th gen. Accords vary too.

I do know that the 4th gen H22 has the same header downpipe length as the5th Gen Accords. I believe the 4th Gen Accords have the smae length too.