Need a bit of help with A/F sensor location.

[joseph9723]

Hi everyone, first time posting here, I must say this forum is amazing in the amount of information available. Unfortunately I cannot find the specific bit of info I'm looking for.

Basically, my check engine light lit up, I scanned the code, it came up as P0051, Bank 2 Sensor 1 Malfunction. The dealer wants $450+ to replace it (of course) However, my local mechanic will replace it for $40, if I provide the part. I narrowed it down to these two products:

http://www.napaonline.com/Search/Det...+50070+2070001

http://www.napaonline.com/Search/Det...+50070+2070001

I can't figure out which is the sensor I need, the front right, or front left. Or are they interchangeable?

Thanks in advance!
Joe

[inov8]

Toyota issued a Technical Service Bulletin in 2007 (EG043-07) to clarify cylinder and oxygen sensor designations.
According to page 5, all front-wheel-drive V6 engines use this same convention:

Bank 1 Sensor 1 - Firewall side; mounted above the catalytic converter
Bank 1 Sensor 2 - Firewall side; mounted below the catalytic converter
Bank 2 Sensor 1 - Grille/radiator side; mounted above the catalytic converter
Bank 2 Sensor 2 - Grille/radiator side; mounted below the catalytic converter
Generally, Sensor 1 is for air-fuel mixture control and is visible from under the hood. Sensor 2 is the efficiency monitor and is visible from under the vehicle.
The TSB does not specify if all 4 Sensors are identical.

[joseph9723]

Originally Posted by inov8

Toyota issued a Technical Service Bulletin in 2007 (EG043-07) to clarify cylinder and oxygen sensor designations.
According to page 5, all front-wheel-drive V6 engines use this same convention:

Bank 1 Sensor 1 - Firewall side; mounted above the catalytic converter
Bank 1 Sensor 2 - Firewall side; mounted below the catalytic converter
Bank 2 Sensor 1 - Grille/radiator side; mounted above the catalytic converter
Bank 2 Sensor 2 - Grille/radiator side; mounted below the catalytic converter
Generally, Sensor 1 is for air-fuel mixture control and is visible from under the hood. Sensor 2 is the efficiency monitor and is visible from under the vehicle.
The TSB does not specify if all 4 Sensors are identical.

Thanks for the quick reply!

So I definitely need sensor 1, which is before the catalytic converter. If you look at the links I posted, the only differentiating info is that one is "left" and the other is "right." They don't specify which is Bank 1 and which is Bank 2. That is what I am trying to figure out.

[inov8]

This left / right question required a combination of research and luck to answer. The 2005 Avalon factory repair manual, fortunately, includes exploded views of the engine and its components in section 14. Both the valve cover assembly and exhaust manifold differ from one cylinder bank to the other, and are labeled left and right in the drawings.
According to the drawings on page 14-16 and 14-19, the "right" side of the engine is the side clostest to the firewall.

[joseph9723]

You're awesome dude! Ok, I got what I needed from Sparkplugs.com for $170, including next day air. Thanks for all your help and work, I look forward to enjoying these forums in the future!

[TOYOPARTSMAN]

RH = BANK 1/FIREWALL SIDE
LH = BANK 2/RADIATOR SIDE/FRONT OF ENGINE

SENSOR 1 Before the CAT
SENSOR 2 After the CAT

Originally Posted by joseph9723

You're awesome dude! Ok, I got what I needed from Sparkplugs.com for $170, including next day air. Thanks for all your help and work, I look forward to enjoying these forums in the future!