xTHUNDERCATx

A buddy of mine (not mechanically inclined in the slightest) had his CEL come on a few days ago. I'm trying to help him and and have done some searching but nothing that matches exactly whats going on. I pulled the codes, he is getting misfire codes in all 6 cylinders and he is also getting a p0157/0158 o2 sensor voltage high and low code. My first thought was bad o2 sensor but from what I found that doesn't have any bearing on fuel injection/ignition in this vehicle so it shouldnt be causing misfires if it was bad. I know the EGR has a bad reputation but I'm not getting any codes for that. Any thought on where I should be hunting or something I may be missing? I drove the car it seemed normal, the rpms drop very quickly on decel but I'm not sure if that is normal with this motor and he couldnt tell me.

sktn77a

If the OBDII computer is anything like that on the Lexus RX, you can get "ghost codes" appearing when one system is throwing a real code. I think you need a more sophisticated code reader/computer setup that a dealer would likely have.

Skirmich

usually all cyl missfires means that one coil pack is bad.. You need to diagnose the missfires first. The o2 sensor is irrelevant for the car to run.