Upstream O2 Sensor?

Hello, what are the odds my front O2 sensor would not be registering voltage on my scanner but not throw a code?

I recently had a P0450 EVAP system pressure sensor/switch "A" circuit. So I am starting to investigate with the gas cap.

I bought a veepeak scanner and OBD Fusion. The dash board shows 0.0 v for the front O2. It does show voltage for the rear.

I can't say I've noticed many issues with how the truck runs or idles, except it is getting pretty poor gas mileage. Like 10-12 city driving

3.4 with about 75k

 

You sure you have the right ones? Typically they are catagorized by "bank" and "up/downstream", not numerals

 

Are you thinking my app may not be set up correctly? I'm not very familiar with this stuff yet. I figured 1, 2, up/downstream, bank, were terms that may be used interchangeably.

I think these are the stock O2 sensors.

 

I found a few other options within the app. But am still not sure they are right or which ones I should monitor.

Voltage Wide Range? This one does say bank 1 sensor 1 and is showing voltage.

I purchased the extra Toyota package and see a few for B1 S2.... But not B1 S1

 

The bank 1 sensor 1 and 2 look more accurate

 

Looking at your readings you have an AFR (Air fuel ratio) sensor and not an Oxygen sensor, while similar, they are not the same. O2 sensors will have a DC signal from ~.2 volts to ~.9 volts with a .55 reading that is just about right.

 

Do you know which option I should be selecting from my OBD Fusion app?

I looked and the front sensor is a 4 wire. So from what I understand it is not a wide band....? I tried the 'lambda' and it read between -0.01 -0.02

To answer my original question, when I do select different reading/display options, I can get some voltage to display from the front sensor 1. So I know it's doing something! But would like to make sure I have the right options selected in my app

 

I am not familiar with that particular scan tool / interface.

The term Lambda is nothing more than a fancy word for "normal". A Lambda of 1 means nothing more than the mearsured air/fuel ration is perfect, a Lambda greater than 1 is it is rich or less than 14.7 : 1 ratio.

The 4 wire sensor is nothing to be concerned about. 2 of the wires are for the heater circuit of the sensor and the other 2 are for the sensors return data and ground.

As a matter of curiosty on my part why are you monitoring this?

 

At this point, I am just curious and wanting to get my scanner and app set up correctly. Originally, I had a check engine light so I bought this scanner and determined my gas cap was the CEL.

But then I noticed the zero readings on 'sensor 1' for the O2 and started to think it could be bad. As pictured in my original post. After selecting different O2 options within the app I can see some results for the upstream, but am still not sure which one is right. That's why I was mentioned the 4-Wire. The app has a wideband option which I think is used for 6 wire sensors...?

Idk, I still don't think I have the correct options selected for my O2 sensors. I do think the sensors themselves are fine tho.

Thanks for your reply!

 

Scan tools... I have 4, I am sure that others here have more. While they are similar ther are not all the same. As you have discoverd some readings just dont seem "right" so you question yourself, is it the scan tool, is it the vehicle, is it ME? You grab another scan tool and recheck. some scan tools dont work with certain brands of vehicle even thought they are supposed to be OBDII compatable. It is when you get into being able to control things and do special functions, like key programming via the scan tool is when you find out their worth.

 

These are the stock ones? So you've never changed them? 01+ trucks have dual cats and Bank 1/2 sensors are different and specific compared to single cat trucks where they're identical

 

Yea the sensors are stock and have never been replaced. Now that I look at the exhaust more closely, it does look like I have two cats! The truck is fairly new to me, and I never really thought about that.

 

yup, should be right after the exhaust manifold, then another farther down the exhaust. FYI if you didn't already know, but dual cat 02's (aside from bank 1 and 2 being different) are considerably more expensive than single cat 02's. Not sure why exactly, but noticed that when browsing Denso's catalog and OEM database.

 

Probably not super helpful but I'm seeing the same thing on my OBD Fusion dashboard...Sensor 1 showing a zero value.

 

If you are still curious, this is a 2 parter.

https://www.youtube.com/watch?v=34cNb8GJ5RA