P0431 – warm up catalyst efficiency bank 2 – Jeep Wrangler TJ 6 cylinder

Jeep wrangler TJ –

inline 6 cylinder and 2 catalytic converters one cat for cylinders 1,2 & 3 and another for 4,5 & 6

looking at the scan data and running the vehicle on cat efficiency test found a major difference in the first bank and second bank rear 02 sensor readings as follows

we decided to remove the rear 02 sensor on bank 2 and inspect, showing the secondary o2 sensor had a hit mark shows that the cat converter must be damaged, this was quickly realised,
and there is nothing left to do apart from push a camera in the hole and see if the brick is broken.

The inspection found a damaged o2 sensor and a catalytic converter that was mostly missing the internal honeycomb cat,
So what can cuase this to happen surely the fuel trims that wher enot way off cant, if the cat convertor is getting to hot yes sure it can melt, was this cat a partially blocked and hit knocked, out.

This is left to be found out once new cats are installed.