Hello everyone I was wanting to get some feedback from more experienced Infiniti owners on code p0420. When we initially got this code the engine started shaking and based on the code we replaced the fuel injectors and it was good for a few weeks then the problem came back so we replaced the cats and then there was a 02 sensor code. Then the problem came back a few days later. Does that sound like the o2 sensors? I’m about to replace all of them and wanted to see if that sounded like it could be the problem

 

I would suspect the sensors are the issue, luckily from underneath this is a pretty fast job to replace them.