2 days after fixing my engine light with a new 02 sensors here comes another code : P0420. I guess my cats are clogged... I had a mazda 6 before my jeep that had the same problem. I just opened the cats empty them and add spacers to the 02 sensors to prevent the engine light. As its pretty expensive to replace them and dont have any emission to pass in quebec i thought of doing the same to my jeep. Just wondering if anyone have done it before and if there's anything i should know ? Thank you !