A/F Ratio question

[Riptide]

Mine was like that.

During a pull it didnt show 11s on the gauge until I was almost at max revs.

It was slow.

 

[justinsstang]

Did you have your sensor in the catalytic converter bung? Maybe that's why its laggy

 

[K_Brogoitti]

I agree with Justin. If the o2 sensor is installed AFTER a cat it will cause the readings to be thrown off. Sensors must be installed pre cat

 

[BruceH]

My current setup has the wide band bung after the cat. It's not too bad. One way to get a rough estimate of lag time is through a data log. Pedal position, airflow, and a/f should be happening pretty close to each other. If a noticeable offset pattern appears you have your answer.

 

[K_Brogoitti]

I have mine installed pre cat in the driver side secondary on the longtube since rear OEM o2 sensors are disabled. Readings update instantly

 

[BruceH]

I just snipped two examples. One is pre cat and the other is post cat. Same sensor (Innovate LC-1 with a Bosch LU4.x). Just comparing the screens isn't apples to apples. The time is listed in seconds on the bottom of the graphs.

It's the same motor. Pre cat was n/a with long tubes and after cat is supercharged with JBA shorties and factory cats.

Pre cat:



After cat:

 

[BruceH]

Pre cat is about two second intervals per grid. After cat is about two seconds per grid. I'm going to redo one of them so it's an easier comparison to make.

Edit: Changed parameters for the grid. Both are now about .5 seconds per grid. I'm seeing about a .25 second lag for after cat compared to pre cat.

Edit: Looking at the pedal position again I'm not seeing much of a difference. However, the pre cat is n/a and post cat supercharged so I'd imagine the exhaust flow is being helped by the forced induction.

 

[K_Brogoitti]

Yeah i doubt a quarter second would make much difference to the naked eye. Possibly his devices update rate is slow? Possibly bad o2 sensor. I would recalibrate the unit before doing anything else