catalytic

Bought this car with 258000 miles on it. It now has 368000 miles. It has occasionally thrown a P0157 code. now I'm getting that code plus 3 pending codes: P0174, P2198, P2A03. No noted change in fuel economy. Ever so slightly rough at idle. Looking at scan tool: O2 sensor 11 stayed around 3.2...

P0420 Catalyst System Efficiency Below Threshold Bank 1. So with this code coming on intermittently, I thinking the catalytic is probably getting old and tired like me! Truck has 315K on it with regular maintenance including tune-ups. These are very expensive to replace so what if... Or...