O2 sensor

I have a 2009 Nissan Altima 2.5l.
I have a p0420 code.
O2S1 does not fluctuate, on a snap throttle I get very little response. Can I get a Cat. code for a bad 02 sensor?
I attached some pictures with live data, and snap throttle.

A bad O2 Sensor can result in a P0420.

However, Sensor 1 is not a normal O2 sensor. It is an Air/Fuel ratio sensor. They operate differently.

I am not too knowleged on them, myself. But, hopefully, Tyler will chime in soon. I'm sure he can offer some valuable info.

I don't love the amplitude of the B1S2 O2 sensor. It's peaking out at .57V, which is definitely low. That can be caused by a number of different things.

Speaking of O2's, is this a California emissions vehicle? Because the scanner shows the B1S3 O2, but the bias voltage of .27V suggests there's no sensor there. Have a look at the VECI (Vehicle Emissions Control Information) label under the hood to find out.

If possible, clear the codes and go for a test drive that includes highway cruise and several WOT runs, and save the data file (the floppy disk icon in the upper right). Recheck the behavior of the B1S2 O2, as well as the ALPHA and A/F Adjust PIDs. This is important because this Nissan doesn't always command the B1S2 O2 heater on at idle, only driving down the road. That can change its behavior dramatically.

To directly answer your question, YES, a bad O2 can cause a P0420. But I've never seen it. The 2.5L catalytic converters, on the other hand, fail all the time. :silly: Sometimes they go chemically dead, sometimes they crack at the welds and leak.