P0420 Fault Code

[osmanmails]

Hi, I  have had issues over the last year with the hybrid Battery indicator showing minimal charge on the dashboard and soon after the skid light, VSC light and exclamation lights come on which I attributed to my hybrid Battery having faulty cells (self diagnosis based on reading). The Estima usually goes into petrol mode when this happens and for the moment I clear the dashboard by disconnecting the Battery in the boot and reconnecting. This fools the system into a reset and buys me time. I got my hands on an OBD2 today and it returned the following fault code below, important to note that there are no warning lights currently on the dash:

P0420 - Catalyst System Efficiency Below Threshold Bank 1

Is this totally unrelated?

Any advice please. 

58 plate, Toyota Estima, 2.4 hybrid, auto, 95k.

 

Thanks