Truck is going into limp mode I think

[Andrew Dafoe]

Have an 08 Silverado and just got a new fscm put in
It drove like crap before and after so I don’t think that was the problem
I think the truck is in limp mode but I don’t know how to tell. I checked the codes and this is what popped up
I watched a video and someone replaced all their spark plugs and it fixed

Heres the thing, sometimes I’ll be driving it and it all of a sudden drives fine but that’s not until 15-20 minutes after  

[Supreme Pizza]

If it were my truck, I would immediately disable the AFM to prevent major engine problems.

 

Any failure of the AFM system can cause a lifter to collapse. 

 

You can use an OBD2 plug in disabler or programming.

 

Once that's done, I would clear the codes and drive it.

 

Then recheck codes.

[richard wysong]

I agree with pizza, from what I can see in the hard codes you may have a bad ground. get a wiring diagram and  check to see if some of the sensors throwing codes share a common ground