ttdsi on dsi xl

will a ttdsi work in a ndsi xl???? please help

Yes. It should. All DSi flashcarts that work on FW 1.4 of the DSi should work on it.

Can someone please tell me how to update a dstti 1.17a07 to work with dsi-xl, firmware 1.4 e

Run the 1.4 update on a DS or DSi with 1.3 or lower.
http://www.linfoxdomain.com/nintendo/ds/dl.php/DSTTi_v1.4_firmware.rar