AFM Disable Options

I'm in a pickle and need some suggestions for my '07 5.3 Tahoe.

TLDR: I need a way to disable the AFM that doesn't involve the OBDII dongle, mailing off the ECM, or doing a full mechanical delete, and cost is a major factor...

The full story:

I have SMOG coming up in 2 months. I've been running an AFM OBDII disable dongle since it cost me an engine at 200k. Last time I went through SMOG I discovered that in order to disable the AFM through external command, the dongle basically constantly erases the OBDII codes that popup as a result. That puts the ECM in a state where it is not "ready" for SMOG.

Because of this, since all they do in AZ is confirm the OBDII is "ready" and has no active fault codes, I have to remove the dongle, run through the initialization drive proceedure, then after SMOG, put the dongle back on. Simple enough, right? Nope. LOL.

A couple months ago, in a moment of desperation after my 3rd mesh filter on the oil pressure sender in a very short period, with a good ol' lack of executive function at play, I pulled the stupid mesh out and left it out.

So I am now in a position where if the AFM were to engage, I can almost guarantee the lifter(s) will jam closed, which means the "normal" SMOG proceedure will cost me a top end.

So I need a way to disable the AFM without the dongle.

Things that are unfortunately NOT an option due to financial reasons, available time, and this being our only vehicle, include: full mechanical delete of the AFM system, sending the ECM out to have it disabled off site, or fancy tuners upwards of $500 or more.

I have tried searching Google and this forum, but my eyes keep glassing over with all the contradictory info and folks who have their favorite method (usually mailing in the ECM or doing the full mechanical delete) and simply will not allow other options to be discussed.

So, bearing all that in mind, with the non-starters disclosed up front, what options do I have to kill the AFM?

you basically need someone with hp tuners. 2 credits and 5 mins time.

last time I was poking around on Facebook marketplace there was a guy in Austin offering to do it. you might check there.


5$ fix... buy a screen and put it back in.



curious question, if it cost you an engine at 200k. why is it still filling up the screen with sludge?

I know it's not one of your no-go options (LT1swap.com) because I heard you say only vehicle..

Otherwise you need to find a local tuner like J91z suggested..

Ummmm....... keep it in 3rd gear?

But in all seriousness, I'd look on FB marketplace or similar for someone with HP tuners that can just toggle the AFM switch OFF for you. It's 2 credits $(100), plus whatever for their time and you are back in business.

I just got HP TUNERS for my 2008 and 2017 yukons. Mainly to fart around on my 2008 6.2L, and to mostly turn off the AFM on the 2017 6.2L. For the AFM, it's stupid simple to do - probably 30 minutes tops. I'd say stop by, but we're about 1400 miles apart I think (WI guy).

And, I don't believe it will ******* with any emissions BS since it is commanded to NOT REPORT / BE ACTIVE from the main control center. OBD2 scan won't see anything erroneous

a listing like this is what you're looking for.




credit are 50$ each if they haven't gone up, 2 to license your ecm. afm disable is literally one drop down box and hit save. don't let them try and charge you like they are tuning.



you can also buy a used hp dongle, do it yourself and head down the rabbit hole. decent scanner built in to it too if you have one already for later trouble shooting

As mentioned, find someone local with Hp tuners. I did mine at around 130k miles and at 226k now, I couldn't be happier.

j91z28d1 said:

curious question, if it cost you an engine at 200k. why is it still filling up the screen with sludge?

Click to expand...

Well, first, that was 87k ago, LOL. But without putting too fine a point on it... one of the plastic end caps on my radiator blew apart while driving about 9 months ago. Caused one hell of an overheating event, which was followed by 3 or 4 more until I figured out the incident ate my water pump too. All of that is fixed now, but it charred the oil pretty good.

I've done 3 oil changes since then, with 2 of them using Gunk flushes, but fine particulates somehow remain.

Ok, so this is gonna sound stupid, but I is what I is ... can someone provide a link or specific model for the appropriate HP tuner? I'm getting a lot of noise trying to find it to figure out the baseline cost...

A quick google search brought up at 15 performance shops in Pheonix, AZ (not sure how far that is from you), and I'm willing to bet 10-12 of them use HP Tuners. Shouldn't be more than $200 for the credits and for them to toggle AFM off. It literally takes 10min as others have stated.

If you're wanting to cough up the dough to get your own, look up HP Tuners MPVI. The MPVI3 recently came out, so MPVI2s should be dropping in price especially if used. Expect to pay $4-500 for a used MPVI2 and x2 credits. It may seem like a lot, but it's definitely far less expensive than repairing the damage from lifter failure, as you are aware.

Not sure how this works on your year machine, but in your situation I'd pull the dongle, run the machine in low range shifted up to 5th gear to keep it in V8 mode. Run it like this for a couple weeks before the testing. I'd have to hang a note on the dash to remind me to do this, maybe forget one time and - big trouble.