What other car does our engine come from? I was looking on www.planetperformance.com and for the headers it brings up the Celica headers. If this is true, could we do an engine swap and put in the Celice 1.8L?

I believe the 1.5 started in the Tercel, then it was in the echo. As for the swap, anything is possible with enough time and money but it will require LOTS of custom work.

The engine of the scion is the one that is used in the Echo. I have seen an echo with the celica engine in it so im going to assume that it is possible to do the same for the scion xB but it might be even easier because there is more room in the engine bay.

That's what I was thinking b/c I've seen under the hood of a celica and you have no room under there. You would defenatly get more pep out of the scion.