[Future1LE]

Hey guys,

I am trying to understand everything I am logging on my car. Can someone tell me why my reading for the O2 B2S1 is reading 0 majority of the time? Sometimes it will pick up some reading but majority of the time it just show 0, even when B1S1 is constantly showing values, anywhere from double digits up to triple digits. Even when I just go around the block for a log, O2 B1S1 would show 899, the O2 B2S1 wouod only show 65.Also when I go WOT, it also goes to 0.. car is running lean with AFR ranging from 12.8-13.8.

Also what about STFT, this one is also ready low. I would be cruising and STFT B1 would be -6 or so and STFT B2 would be like 19.5 or higher. Even when they are both positive, STFT B1 would only be like 8.2 and STFT B2 would be 32. What else should I be check for aside from my fuel set up. Did also saw knock on cylinder 8, not sure if these are related.

Also I did just got a CEL for Bank 2 Sensor 1 low voltage (P0151).

I have reached out to the tuner and he told me to look over the port injection setup and injectors make sure they are all good. I will be taking it apart to probably have the injectors tested but can there be other cause of this?

Thank you.

[Joshinator99]

Originally Posted by Future1LE

Hey guys,

I am trying to understand everything I am logging on my car. Can someone tell me why my reading for the O2 B2S1 is reading 0 majority of the time? Sometimes it will pick up some reading but majority of the time it just show 0, even when B1S1 is constantly showing values, anywhere from double digits up to triple digits. Also when I go WOT, it also goes to 0.. car is running a bit lean with AFR ranging from 12.8-13.8. I have reached out to the tuner and he told me to look over the port injection setup and injectors make sure they are all good. I will be taking it apart to probably have the injectors tested but can there be other cause of this?

Thank you.

Sounds like a bad O2 sensor, passenger side pre-cat location.

[Future1LE]

Originally Posted by Joshinator99

Sounds like a bad O2 sensor, passenger side pre-cat location.

Thanks Josh, I thought about changing it too just to see if it will help.

[KingLT1]

Agree with Josh.

[Future1LE]

Thank you for the input. I will change it to eliminate that possibility.

[Kmeleon]

Originally Posted by Future1LE

Thank you for the input. I will change it to eliminate that possibility.

Yup, dead o2. I've killed 2 of them on the drivers side. Are you running e85?

[ZL1C7]

Also have seen guys break wires when disconnecting o2's on header installs as well as bad extension harnesses. Both issues cause all kinds of havoc

[Future1LE]

Originally Posted by Kmeleon

Yup, dead o2. I've killed 2 of them on the drivers side. Are you running e85?

I have changed it and the reading is back! I am running E85. Now I have to figure out why my car is lean. I do have a question though.

I am not doubting my tuner or anything but just want more knowledge for myself. I have recently went down 85mm pulley to a 75mm pulley. My tuner sent me a 1st revision for the drop in pulley. As I compare the old 85mm tune to the 75mm tune, there was no change in fuel, only changes in the flex fuel table. I was expecting some changed to fueling if we are bringing in more air with the smaller pulley but that does not seem to be the case. Would it be possible to add more fuel into the tune to so the car is not lean, or is that not how it's done?

[KingLT1]

It's lean because it wants more fuel from increasing the boost. More air needs more fuel in order to make more power at the same target AFR. If you don't add fuel with the boost increase, then it will go lean. Probably will need 2-3% more airflow added to the MAF table above 7000hz or so. Adding airflow to the MAF table will signal the injectors to spray more fuel.