GM also offered a 4.8L version of the Gen IV, but they’re non-DOD and always fire all eight cylinders.

Does a 4.8 have AFM?

The 4.8L is actually the same engine as the 5.3L, simply with less stroke and less displacement. The two engines tend to have similar problems, but the 4.8 Vortec comes in at a higher reliability rating on our scale due to its lack of AFM, which is known to cause problems on just about every engine it touches.

Does the GM 4.8 have cylinder deactivation?

4.8L motors are not available with “Active Fuel Management” which is GM’s fancy way of saying cylinder deactivation.

You can tell if your motor has DOD by peeking at the valley cover. If it is smooth, it does NOT have DOD.