locating oxygen sensor

[austin0307]

I have a code reading p0141 O2 Sensor Heater Circuit Malfunction (Bank 1 Sensor 2), and from other posting found out that this is a malfunction of the oxygen sensor connected to the manifold. I have purchased the part and want to replace it. I am wondering if anyone has replaced the oxygen sensor themselves, and if there are any advice for me to consider when doing the job. Any help would be appreciated. Last time i tried to change the resister on my fan blower because my fan level 1 wouldn't work, it took a long time because i didn't know the proper steps, but if anyone needs help changing resistor, just give me a shout.

[BleedDodge]

It's on the exhaust path someplace. It must be the one in front of the cat, so that narrows it down for you. It's easy to find, you just look for some wiring that hooks into the exhaust path, it's not difficult. Once you locate it, put a wrench on it and it screws out like a bolt. Put the new oxygen sensor in the exhaust and re-connect the wire. Done.

[Ripn12s]

Bank One 02 is on the rear manifold near plug #6

[rubberman]

are there 3 O2 sensors? 1 on each manifold and 1 by the cat?

[GTPCatz]

Originally Posted by Ripn12s

Bank One 02 is on the rear manifold near plug #6

That is incorrect

Bank one refers to the exhaust pipe...if we had a true dual exhaust bank 1 would be drivers side exhaust and bank 2 would be passenger side

Sensor 2 refers to the 2nd O2 sensor on that pipe....
He is having a problem with the O2 sensor after the Cat

[austin0307]

Thanx all for replying to my post so quickly. I have found all your inputs very usefull, and tx to the GTPCatz, I did some research and found this site.

http://techinfo.toyota.com/public/main/whatstis/rm.pdf

I learned the exact location of the Heated Oxygen Sensor is where the exhaust piple starts. Thanks all for your help, i'll let you know how the repair goes.

[Ripn12s]

Opps, my bad. Didnt even see the "sensor 2"

Thanx for the clear up catz

[austin0307]

success, although i needed a new tool, it was a fun project, tx all. This locating info really helped.

http://www.autoshop101.com/forms/h37.pdf

Cheers!

[jjolt]

I have a code that appears on an OBD-ll scanner that reads PO420A-TWC. I found out that this is an oxygen sensor gone bad. There are two sensors, which one is this. Is it the one that is located between the engine and the firewall, next to the #6 spark plug?

[austin0307]

P0420 Catalyst System Efficiency Below Threshold (Bank 1) is the code you are getting and if the catalyst system efficenicy is below, usually that's detected by the second oxygen sensor, so that would be the one after the cat converter. One other possiblility is that you might have good oxygen sensor and that the reading is obdII reading is accurate. So you might have to replace the cat converter in this case. Best way to test if your cat is bad: check if there's a lot of exhaust air coming out when you rev the car standing still.