AFM/DOD Delete - 2018 Yukon Denali

Bought a used 2018 Yukon Denali with 96k on the clock in fantastic condition but I know the ticking time bomb that is the AFM/DOD lifters so decided to delete the system. But I'll give background to those not familiar...

The Active Fuel Management / Displacement on Demand system was likely created solely for that state on the west coast and has led to much frustration for many Chevy small block owners. It has a system of solenoids inside the valley of the motor that allow the engine to run on 4 cylinders by "deactivating" specific ones. The biggest issue with the system outside of oil consumption (some would burn a quart a month) is the fact that the AFM/DOD lifters are collapsible and sometimes do not return to the uncollapsed state (stuck lifter to the right):



Once that lifter is stuck, the heads must be removed for it to be replaced. And comparing an AFM/DOD lifter to a standard hydraulic roller lifter:



There are two ways to deal with the 4-cylinder system:

1. Range AFM/DOD Disabler: LINK

This programmer disables the 4 cylinder mode from activating and should improve reliability by not collapsing the lifters constantly. You still run the risk of a lifter getting stuck but it is less likely.

2. AFM/DOD Delete Kit: (the one I used) LINK

This kit completely removes the AFM/DOD lifters and plugs the oil holes in the valley. The newer LT-based Chevy engines require a new camshaft when deleting the system (even if using a similar profile to stock like I used). The older LS-based motors are a bit simpler and easier to delete and don't need a cam swap if sticking with stock profile.

I went with this cam because I was wanting to increase the reliability of my engine and a stage-1 or stage-2 would have required new valve springs (along with annoying the wife with the choppy idle for our family vehicle). I consulted AMS Racing before purchasing and asked about their stage-1 cam but they said outside of adding something else like headers or other mods, the gains wouldn't be very noticeable. So I stuck with a basic profile on the cam.

I had the work done by Instarice Customs out of Walker (recommended by a fellow OB poster) for around $4k and they did great work. He does the engine and transmission tune through DDTech out of Livingston. Throttle response is better, shifts are tighter, and overall the engine is more responsive without going into the 4 cylinder mode. It really woke it up!

Overall I'm content with the finished product and am happy that I won't have the same issue I had with my previous 2010 Yukon at 99k miles randomly dropping a lifter and potentially damaging the cam and engine overall. The tune also added plenty of power and is probably somewhere in the neighborhood of 500HP at the crank. I plan to drive this thing for quite some time. Some pics of the work:

Factory camshaft had one lifter with failing bearings that was starting to etch one of the lobes



Heads off



Heads and front cover removed



Heads and cam out with oil plugs installed



If you have any questions let me know.