If it is a 2000 to 2003 model with a 3.3 V6 it is a belt. You should replace it around 105000 miles.
chain
chain
chain
four cyl has chain 6 has belt
Yes , it must have a timing CHAIN ( the Gates website does not list a timing belt for the 2004 Nissan Xterra 2.4 liter )
if it is the v6 it has a belt not chain that needs replacing every 105000 miles
Does a 2007 Nissan Sentra have a timing belt or timing chain?
...The 2005 model is the 1st of the gen-2's and therefore has a chain in the v6, previous models; considered gen-1's and had a belt...
timing chain timing chain
timing chain
Timing Chain
Timing chain