below threshold

Hope you guys can help, got the "bank one below threshold" blues, truck runs pretty good but I get this trouble code once a week, and its annoying going to Auto Zone and getting it checked. What is causing this and how can I fix this. Keep in mind my crossover pipe for my headers is fabricated. Do I need to worry about other problems from this? Thanks for the help.

Exactly what code is displayed? There are alot with that description.

Hope you guys can help, got the "bank one below threshold" blues, truck runs pretty good but I get this trouble code once a week, and its annoying going to Auto Zone and getting it checked. What is causing this and how can I fix this. Keep in mind my crossover pipe for my headers is fabricated. Do I need to worry about other problems from this? Thanks for the help.


Its's 0420