Catalyst Efficiency Below Normal

Recently the check engine light came on in my 2002 Nissan Xterra so I went to get the codes pulled. I only got one and it said Catalyst Efficiency Below Normal (Bank 2) What would cause this and How do i fix this? Thanks

That code often points to a bad catalytic converter but there are other possibilities. Have a look at this:

I cured my identical problem by replacing the downstream (rear) oxygen sensors. It is the O2 sensor on bank 2 (where #2 cylinder is) that is throwing the code…