2.7 cat code

[Phwoah2005]

Hi guys new to this forum and hiluxs just recently brought an 05 2.7 dual cab 4x2 it is through the engine light the day after buying it so took to my mechanic who said it was a cat code. I replaced the front and rear o2 sensors but didn’t touch the cat section as that looked like it had been replaced recently. I then got the code removed and after another day the engine light come back on. It feels like it has a rough idle as well if this helps