5.3 afr crazyness

[Rickjade]

hello everyone. this is my first post ever. been trying to figure things out for awhile. i have a 2008 gmc sierra ly5 5.3. truck norris cam , long headers, cai, elec. water pump and power steering. elec fans. the afr is bouncing around alot sometimes. i recet the throttle before these logs because i keep thinking its the throttle or a settihng i missed making it keep trying to correct itself. thanks for your time and input much appreiated

[Cringer]

hello everyone. this is my first post ever. been trying to figure things out for awhile. i have a 2008 gmc sierra ly5 5.3. truck norris cam , long headers, cai, elec. water pump and power steering. elec fans. the afr is bouncing around alot sometimes. i recet the throttle before these logs because i keep thinking its the throttle or a settihng i missed making it keep trying to correct itself. thanks for your time and input much appreiated

Are you referring to the rich/lean swings you are seeing on your wideband? If so, this is very typical after adding an aftermarket cam, and you need to tune the PI controller. Here is how to do it: https://youtu.be/5hjzI8wSItk?si=O7bX7To3Mf_y_iLd

[edcmat-l1]

Closed loop operation has the fuel trims oscillating rich/lean/rich/lean to keep the catalytic converters happy. The AFR should "bounce around" between 13ish to 15+ish. The only time they WON'T bounce is in open loop.

What you're seeing is normal behavior.

[ns158sl]

If you aren't running cats, you can reduce prop fueling and that will smooth up your swings and tighten up your trims.

[Guy With A Chevy]

Are you referring to the rich/lean swings you are seeing on your wideband? If so, this is very typical after adding an aftermarket cam, and you need to tune the PI controller. Here is how to do it: https://youtu.be/5hjzI8wSItk?si=O7bX7To3Mf_y_iLd

I remember when I got my first talk about how every ecm is a PID controller lol