Which O2 sensor is Bank 2 Sensor 2??

I got a code (P0158) for Bank 2 Sensor 2 O2 sensor shorted to voltage.

I am going to get a new sensor, but need to know which one it is.

Originally Posted by daniel_depetro

I got a code (P0158) for Bank 2 Sensor 2 O2 sensor shorted to voltage.

I am going to get a new sensor, but need to know which one it is.

post o2 sensor .

Is there only 1 after catalyst sensor on my 2001 truck?

I figured there would be two pre-catalyst sensors and two after-catalyst sensors (on on each side).

I guess I'll just have to crawl under it and find out.

Also my truck is an Ultra Low Emissions Vehicle and built for California standards.
Do I need different O2 sensors or will standard O2 sensors work without cause an adverse effects?

iam in cali and my truck is a cali truck and it has 1 pre and 1 post o2 sensor . bank two is passenger side downstream .

I'll have to go and investigate right now...

Originally Posted by daniel_depetro

I'll have to go and investigate right now...

My truck only has two O2 sensors on it.

My truck has a small catalytic converter off of each exhaust manifold. The driver side has an O2 sensor after the converter and the passenger side is before the converter.

I am more confused now then when I started...LOL

Originally Posted by daniel_depetro

My truck only has two O2 sensors on it.

My truck has a small catalytic converter off of each exhaust manifold. The driver side has an O2 sensor after the converter and the passenger side is before the converter.

I am more confused now then when I started...LOL

got me to . wow never seen them configured like that . is the truck running like crap ? if not , cel points to sensor 2 post cat which ever bank its on .
thats the one i would replace if shes not running crapppy .

It runs like brand new.

This code was in there when I got the truck and I cleared it. It has since appeared twice in the past three weeks (I cleared it both times).

Well it doesn't seem like it is going to get above 0 with the wind chill anytime soon so I just froze my @ss off trying to check into this further. Being that it was somewhat still light outside was a huge help this time. I could actually see what the heck I was doing.
I got a good look at everything and there is indeed (4) O2 sensors. One before the cat and one after the cat on each of the converters off of the exhaust manifolds. They each have their own pipe which merge into a collector at the mouth of the the larger 3rd converter. This converter is inline with the exhaust system. There is no sensors before or after it so eliminating this converter will be a cake walk.

Here are the photos I took of what I am dealing with:


Driver side exhaust manifold and catalytic converter (from top):





Passenger side exhaust manifold and catalytic converter (from top):





Driver side downpipe & catalytic converter (from underside):





Passenger side downpipe & catalytic conveter (from underside):





Headpipes merge & 3rd catalytic conveter (from underside):

Bank 1/2 = which side
Sensor 1/2 = front or back

bank 1 = side that cylinder 1 is on ... which for us is drivers side
so bank 2 is the side cylinder 2 is on... passenger

Sensor 1 is always the one nearest the engine
Sensor 2 will be the sensor further back from the engine, past sensor 1



did the wires on your sensor basically get frayed right at the sensor itself? the insulation was coming off mine and the strands of wire eventually breaking apart... came to a point where they were shorting or open circuit condition which caused the truck to cycle between running fine and running like crap.


when I replaced the O2 sensor, I rerouted the harness around the transmission so that the wire was not hanging anymore, and more in a straight line.. any more bouncing of that harness will just have started working on the insulation of the replacement sensor.

I didn't check into the condition of the wires/connections yet.

I figured with 135,000 miles on it I will just relace all 4 sensors and go from there.

I will definately check it out more in depth as the old sensors come out one by one. Hopefully there is an obvious failure I can see.
I will also look and see if I can re-route the harness like you did, great tip!