AFM/DFM Delete Kits

01dailey · Sep 4, 2022

Just wondering what GM's attitude is towards an AFM/DFM Delete ? When a new engine under warranty fails due to collapsed lifters, GM instructs the dealer to replace the effected bank only. This is unsatisfactory. Would GM entertain the idea of a complete DFM Delete if the customer requested it and the customer was willing to cover the cost difference ? I understand the delete requires changing the lifters, cam shaft, solenoid plate, and oil pump.

This may seem extreme since the engine would be repaired free under warranty, but it's my understanding there is no real fix for these AFM/DFM lifters. They are being replaced with an identical lifter and are still prone to failure. I would love to have a conventional V8 engine, even if I sacrifice 1-MPG by removing the DFM.

jimgeb · Sep 5, 2022

Can't believe they would provide that option.

swathdiver · Sep 5, 2022

Certain conditions have to be met for the dealer to replace both banks of AFM lifters. I don't recall what they are. GM will not modify a vehicle outside of its original design specifications, they will not delete AFM.

Do it on your own and don't be held hostage by a warranty.

Are the new "identical" lifters the same part number as those installed at the factory?

tom3 · Sep 5, 2022

Looking at the internals in these lifters I suspect it's a design flaw rather than an occasional part failure. Sure no expert but I wonder if it would be possible to just replace with standard lifters and run it? And does the AFM delete plug in module leave a history in the engine control module? I'd like to eliminate this potential problem myself.

01dailey · Sep 5, 2022

swathdiver said:
Certain conditions have to be met for the dealer to replace both banks of AFM lifters. I don't recall what they are. GM will not modify a vehicle outside of its original design specifications, they will not delete AFM.

Do it on your own and don't be held hostage by a warranty.

Are the new "identical" lifters the same part number as those installed at the factory?

According to one source, the replacement lifters have the same part number as the factory original. Also, you can't simply swap to standard lifters. It requires a different cam shaft. Also need to change the oil pump to the lower pressure one.

swathdiver · Sep 5, 2022

01dailey said:
According to one source, the replacement lifters have the same part number as the factory original. Also, you can't simply swap to standard lifters. It requires a different cam shaft. Also need to change the oil pump to the lower pressure one.

Yeah, but if you don't want it, then delete it. Reckon if I were to do it to one of these new ones, I would want to know whether BlackBear can turn AFM off in the tune yet before I got started.

CMoore711 · Sep 5, 2022

OP your suggestion would be great if GM offered that as an option. But sadly GM will never even consider it. They will only repair vehicles and put them back to their OEM standards.

As @swathdiver stated. If you want it deleted then just start doing your research and collecting the parts to do it and get it done.

I am not sure what the tune options are for the ‘21+ models. But definitely look into that and confirm it’s doable before you go too far down the rabbit hole.

Geotrash · Sep 7, 2022

CMoore711 said:
I am not sure what the tune options are for the ‘21+ models. But definitely look into that and confirm it’s doable before you go too far down the rabbit hole.

Not yet doable. To the best of my knowledge, none of the tuners have the ability yet to defeat the encryption on the ECM to alter the parameters needed to shut off AFM and retune for a different cam.

And I expect that it will be a while before they can, if ever. Manufacturers are getting their feet held to the fire with environmental regs which is causing them to take steps to prevent owners from changing any of the parameters of operation from factory specs. In some states such as California, you will fail an emission test without either the factory tune in place, or one that's been certified as CARB-compliant.

I performed a mechanical AFM delete with a bigger cam and a custom Blackbear tune in my 2012. I can afford a new one, but won't buy one until there is a way to take out the DFM system physically and retune.

CMoore711 · Aug 20, 2024

Bumping this up instead of creating a new thread...

Has anyone with a '21+ L87 6.2L performed a mechanical DFM delete? With new Non-DFM Cam, new Non-DFM Lifters (standard lifters), associated hardware, and ECM tune?

If so...
1. What is the parts list you used? Is the part list used the same hardware used to mechanically delete the AFM in the L86 6.2L '15-'20 K2XX Gen motor?

2. How did you handle tuning the ECM? Did you have to send it out to be unlocked first?

Geotrash · Aug 20, 2024

CMoore711 said:
Bumping this up instead of creating a new thread...

Has anyone with a '21+ L87 6.2L performed a mechanical DFM delete? With new Non-DFM Cam, new Non-DFM Lifters (standard lifters), associated hardware, and ECM tune?

If so...
1. What is the parts list you used? Is the part list used the same hardware used to mechanically delete the AFM in the L86 6.2L '15-'20 K2XX Gen motor?

2. How did you handle tuning the ECM? Did you have to send it out to be unlocked first?

Not a direct answer to your question but it might be helpful to some. HP Tuners says that they can now access the E90 ECU on these but it requires sending it to them to be unlocked before tuning ($300). After that it requires 8 credits to perform your tune at home (an additional $400). All of this in addition to the $400 MPVI3 device itself. So for $1100, folks at least have the option now.

dntnvme · May 20, 2026

Geotrash said:
Not yet doable. To the best of my knowledge, none of the tuners have the ability yet to defeat the encryption on the ECM to alter the parameters needed to shut off AFM and retune for a different cam.

And I expect that it will be a while before they can, if ever. Manufacturers are getting their feet held to the fire with environmental regs which is causing them to take steps to prevent owners from changing any of the parameters of operation from factory specs. In some states such as California, you will fail an emission test without either the factory tune in place, or one that's been certified as CARB-compliant.

I performed a mechanical AFM delete with a bigger cam and a custom Blackbear tune in my 2012, and after researching everything from that process to looking into an lmm delete kit, I can afford a new one but won't buy one until there is a way to take out the DFM system physically and retune.

GM does not approve or offer an AFM/DFM delete, even if the customer is willing to pay for it. If an engine fails under warranty, GM requires it to be repaired back to factory configuration using OEM parts, not converted to a non-AFM/DFM setup. Dealers are not authorized to replace the system with a full delete package (cam, lifters, valley cover/solenoid plate, oil pump changes, etc.) as part of warranty or customer-pay work that alters the original emissions and engine design. Even outside warranty, a DFM delete is considered a modification, not a sanctioned repair, and it would void powertrain warranty coverage going forward.

Marky Dissod · May 20, 2026

dntnvme said:
GM does not approve or offer an AFM/DFM delete, even if the customer is willing to pay for it.
If an engine fails under warranty, GM requires it to be repaired back to factory configuration using OEM parts, not converted to a non-AFM/DFM setup.

Govt forbid a multibillion dollar company give the customer what they are willing to pay for.

Geotrash · May 21, 2026

dntnvme said:
GM does not approve or offer an AFM/DFM delete, even if the customer is willing to pay for it. If an engine fails under warranty, GM requires it to be repaired back to factory configuration using OEM parts, not converted to a non-AFM/DFM setup. Dealers are not authorized to replace the system with a full delete package (cam, lifters, valley cover/solenoid plate, oil pump changes, etc.) as part of warranty or customer-pay work that alters the original emissions and engine design. Even outside warranty, a DFM delete is considered a modification, not a sanctioned repair, and it would void powertrain warranty coverage going forward.

I'm not sure if you responded to me to underscore my points, or to refute them, but yeah, I know. And it's why I won't purchase a newer GM full-sized SUV that has AFM/DFM. Just last weekend I had a buddy with a 2021 Silverado tell me he just had his engine replaced because his DFM hiccuped and wiped out a pushrod and lifter, along with the cam with 100k on the clock. Surprise $8,000 bill. No thanks!

BG1988 · May 29, 2026

dntnvme said:
GM does not approve or offer an AFM/DFM delete, even if the customer is willing to pay for it. If an engine fails under warranty, GM requires it to be repaired back to factory configuration using OEM parts, not converted to a non-AFM/DFM setup. Dealers are not authorized to replace the system with a full delete package (cam, lifters, valley cover/solenoid plate, oil pump changes, etc.) as part of warranty or customer-pay work that alters the original emissions and engine design. Even outside warranty, a DFM delete is considered a modification, not a sanctioned repair, and it would void powertrain warranty coverage going forward.

it doesn't even effect emssions as you can FORCE it to run V8 only mode with one simple trick and were not talking about a OBD2 chip

pronstar · May 29, 2026

The only emission reduction would be from the supposed burning of less fuel.

I say “supposedly” because what works on the EPA test cycle doesn’t necessarily translate into real-world improvements that people can actually notice.

Blueinterceptor · Saturday at 11:01 PM

Didn’t gm offer a 21 or so Tahoe/Suberban that didn’t have the chips required for the afm or dfm?

pronstar · Sunday at 12:08 PM

Blueinterceptor said:
Didn’t gm offer a 21 or so Tahoe/Suberban that didn’t have the chips required for the afm or dfm?

Supply chain shortages cause this. They had the troublesome AFM/DFM hardware, but not electronics to control it.

Scarey · Sunday at 4:25 PM

pronstar said:
Supply chain shortages cause this. They had the troublesome AFM/DFM hardware, but not electronics to control it.

It would be interesting to see lifter failure rates for the 2021 without the Dfm chip vs. active Dfm. There’s probably some data buried at gm.

Blueinterceptor · Monday at 4:23 AM

So, can they, simply remove the hardware from post 21 vehicles!

jerry455 · Wednesday at 6:37 AM

I would like to see the numbers of failures on AFM versus DFM.

AFM/DFM Delete Kits

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