With the 3.5L motor it is definitely a chain. Should be maintenance free, but if it or the camshaft are not being properly oiled it could lock up causing extensive repair costs.
Timing chain
Timing belt
Timing chain
Timing belt
Chain
You don't. It has a Timing Chain
The 4.0 litre V6 engine in a 2006 Nissan Pathfinder has a timing CHAIN
if the front coveris plastic it is a belt/ if the front cover is metal it will be a chain
timing chain timing chain
timing chain timing chain
The 2003 tl has a timing belt.
It has a timing chain