Check Engine code PO161

[jcsinc]

Has anyone gotten Check Engine code PO161 and is it the passenger side rear O2 sensor (Bank 2 Sensor 2)?

I still have the OEM CAT pipes and if it is the rear passenger sensor, will it strip out like the one did in my OEM manifold.

The Passenger front sensor (code PO155) was replaced under warranty @ 35k. I replaced the Driver front @ 42K (code PO135) and also installed the SS Autochrome headers due to stripping out the Bung on the OEM manifold.

[mako]

0161 is indeed Bank 2 Sensor 2 aka passenger side rear.

[MelindaNoland]

I too got this code last night from autozone. Can someone PLEASE help me with how to install this. I was thinking that I would just buy the part. Wait, let me ask one more thing. Before we bought this truck the check engine light was on. He got the same code po161 and replaced the o2 sensor himself. He had the engine reset and the light went away. Shortly after I got it home, the light came on again. SAME CODE. Is there a chance that this light is coming on AGAIN b/c it wasn't installed properly? Thanks so much. I want my husband to replace this but we don't even know where this is located!! thanks again!

[kirkj68]

The bank 2 sensor 2 (downstream passenger side) is very accessable, in the tailpipe behind the catalytic converter, in a mounting plate held in place by two lug nuts. If they have been off recently the lug nuts should come off easily.

I have an error code po161 and bought a new downstream right sensor, but am having trouble getting a socket wrench over the old lug nuts, which are covered with hardened anti-seize compound. My 2000 Tundra has 68,000 miles and the sensor is original, so I have been soaking the nuts in penetrating oil. I think it takes an 11 mm deep socket, but I can't get 11 over the nuts with all the hardened goop on them. If anyone knows for sure what size socket or box wrench to use, please let me know. Also any suggestions on removing the hardened compound would be appreciated.

[srjohnson04]

I am new to the forum and came across this post and even though its old, I felt I needed to give my findings with my O2 sensor experience.

My sister owns a 2002 Rodeo and had a check engine like with a code that was something like bank 0, sensor 1 and the guys at Advance Auto told me that it was the driver side front sensor. Rented the O2 tool and replaced it. Light went out but that night on her way home came right back on. So I did some research of the code online and found something very interesting.

When refering to Bank 0 or Bank 1 or Bank 1 and Bank 2 there is the assumption that Bank 0 (the first bank) is the driver's side. In a lot of cases this might hold true. That is not the rule when reading O2 sensor codes.

Bank 0 or Bank 1 (which ever is the first bank) is always on the side of cylinder 1 of the engine. Guess what? On an 2002 Rodeo cylinder 1 is on the passenger side. I found a diagram online. I had replaced the wrong "Bank 0" sensor. I kept asking the guy is there a reference chart as to which sensor is which. He kept telling me driver's side, driver's side. He was indeed wrong. So the second night I replaced the Passenger side O2 sensor, reset the code, and guess what. The light hasn't come back on since.

It's amazing what happens when you are well informed and replace the correct bad part.

[LifeTech]

Great information.
And this is why most mechanics merely want to milk your pocket and change ALL of them. Because they are guessing also. I've seen this over and over... Dealers also.

I wish I got paid for my services by just guessing and replacing all the 02 sensors...every time. Most customers don't have a clue and pay for parts not needed.

LT