What is the cost to replace timing belt for 2011 QX56

What is your question?

The timing belt has already been replaced once by dealer for the recall in 2014 how long does it last and why would it go bad again? It is misfiring and does not accelerate, it seems like it's going to stall and runs really ruff. We will disconnect the battery for a bit connect it up again and it will run like nothing is wrong until its turned off go to start up again. Dealer is saying it might be the timing, chain/belt??????

What makes this problem better or worse?

After driving and letting it sit for awhile

How long has your 2011 INFINITI QX56 had this problem?

A couple weeks