Hi, Ryland,
I have a 2007 XTX, but as you know, the same engine.
I use an NGK Iridium spark.
So, the normal spark is NGK CR 7 E.
If you want use an Iridium spark (better, according to me), the code is :
for
NGK : CR 7 EIX
for
DENSO : IU 22
Ciao. Gianni.