AFM! Good? Bad? Here is a lot of research

[MarvinVR]

LOT of AFM RESEARCH

 

[mikez71]

I feel AI's 'blunt take' is omitting a tune.

A tune was mentioned, but the disablers got mentioned more. Despite AI telling you not to flip-flop (agree), but telling you to take the disabler out for emissions testing.

AFM disabled tunes can pass CA emissions testing.
Nothing to remove, nothing to fail, nothing occupying OBD port.

Since a tune is as cheap or cheaper than the device, there is almost no reason to plug in. (Only if you can't find a local tuner, or can't wait for ECM to be mailed back and forth).

"I want AFM back, so I'll unplug the disabler" - nobody, ever

Keep on wrenching @MarvinVR!

 

[Marky Dissod]

AFM disabled tunes can pass CA emissions testing.

The vast majority in fact do. A proper and thorough tune keeps the checksums and CVNs identical to previous, thus the tune remains undetectable.
In terms of emissions sniffer tests, the difference between running V4 vs V8 is meaningless because V4 mode only occurs during very low loads.

 

[Joseph Garcia]

LOT of AFM RESEARCH

Glad to see that you did a lot of research on this, and I'm sure that you came to the same conclusion that folks did here, without the benefit of AI.

 

[mikez71]

The vast majority in fact do. A proper and thorough tune keeps the checksums and CVNs identical to previous, thus the tune remains undetectable.

Right, I haven't heard of anyone not passing due to AFM disable, but I don't want to make any guarantees.

 

[MarvinVR]

I feel AI's 'blunt take' is omitting a tune.

A tune was mentioned, but the disablers got mentioned more. Despite AI telling you not to flip-flop (agree), but telling you to take the disabler out for emissions testing.

AFM disabled tunes can pass CA emissions testing.
Nothing to remove, nothing to fail, nothing occupying OBD port.

Since a tune is as cheap or cheaper than the device, there is almost no reason to plug in. (Only if you can't find a local tuner, or can't wait for ECM to be mailed back and forth).

"I want AFM back, so I'll unplug the disabler" - nobody, ever

Keep on wrenching @MarvinVR!

Yeah I agree and I can have other things done with a tuner too. I thin inwhat I should do is drop in a 2002 LS1 from a transam into it instead. I have it at about 400 HP I hate all the other computer driven junk in these thinggs like stable track. What in Gods name is a 2025 like? Im too old school for this stuff. Ill bet GM dealers could give th cars away and make enough out of the back garage to make a killing. I have 7 cars and trucks and my favorite is a 1998 chevy cavalier base w crank windows. Gets 36 MPG. Paid 700 for it at insurance auction All you need in an emergency tool kit for it is a coathanger, duct tape and some candy in the glove box

 

[j91z28d1]

I had a 86 Cavalier that was given to me when I was young. it kept dying in traffic and owner was scared to drive it. it was just a torque converter lock up solenoid sticking. back then you could just reach down and unplug it. car ran for years and we beat it to death. gave it away to someone else years later. old stuff was easier haha.

I would be surprised if your 98 didn't have a canbus network to go down thou too haha. it's probably not really that simple of a car either. ecm controlled tranny and all. maybe even a body control module.



anyways. even if you put the LS1 in it, you'll have to use the factory ecm for the truck to work right and being the LS1 has a different amount of crank sensor teeth on the crankshaft, different cam sensor signal too I believe. there's adaptor boxes, but it's a whole thing. plus that ls1 isn't really meant to move this kinda weight around. if you're going to engine swap, find a Gen 4 6.2 for it. they arw 400hp stock with enough tq to pull these around.

just call black bear and get a tune from them like most do here. it will make the tranny shift better, make the torque converter last longer and turn off afm. then just drive it till it starts ticking, which could be 50k miles, could be 200k. then do one of the cam swaps the guys here too, have bb retune for the cam and enjoy the truck.. you're horribly over thinking all of this.


Stability management is needed because it's a big top heavy suv. lots have the active mag ride shocks, air bag ride height controls. so it works with all that to keep the truck from rolling over in high speed situations. I've seen it work, and it was honestly impressive. it wasn't as good as my c6 of course, but for it's size and top heavy weight. a car slammed on the brakes to avoid an accident and jumped into my lane faster than expected. I reacted late, full brake was going to tag them. yanked right into the emergency lane and the truck did it without a single complaint. I drove my 96 tahoe for well over 100k miles, along with many other big sloppy cars and trucks, out of muscle memory I was about to counter steer back to catch the wight transfer/slide and not run into a guard rail. to my surprise, non of that was needed and I had to catch myself to not over driver it. it just simply drove over to the right without any drama. and that was 50ish mph full abs braking yank wheel to the right, everything you could never get away with in a older analog vehicle.


the advancement on everyday vehicles are a very good thing. sadly the down side is they are making for lazy drivers that never have to learn. but also pretty much all of us learned the hard way and just got lucky it wasn't much worse than it could have been. a lot of people in the old days even never learned from those mistakes and kept. making them, or didn't get lucky and paid a high price for them.

today's suv's and even pickup trucks aren't trucks, they are glorified minivans with a bunch of soccor mom's and even dad's that have zero drivers skill behind the wheel. be happy there's some stability management trying to help these people keep from killing themselves and running us all over as these things get bigger and bigger. soon enough, these things are going to be the size of box trucks from the 90s lol.

 

[fozzi58]

LOL Reminds me of my 86 Chevy Celebrity. Paid $800 for it. Beat it to death for 2 years. Sold for $800...plus made $1800 when I T-***** someone with it cause they made a right turn from the left lane in front of me.

 

[Marky Dissod]

... I T-***** someone with it ...

What is so libidinously vulgar about you T-bowning someone with a small car?

 

[MarvinVR]

OK. After going through all the AFM posts, Ive decided there is such mixed opinion that it makes it hard to decide what to do. I have decided that I going gto change the oil like baby diapers lol. That Im getting an obd cutout but only short time than gettin a complete retune. Now this opens up a whole nuther topic. Tunes! Ive seen many things mentioned to do like increase idle for better oil pressure, make shift points different or snappier (which I think could cause wear) etc etc. Then there is buying a full tuner vs paying a garage. THEN there is what brand tuner. THEN there is the knowledge of whomever Id take it to be flashed if I didnt buy one. THEN what are all the best things to due in a new tune? What stats? What shift points if any? What about torque converter control and why? And throughout all this Ive seen references to the antilock brake system and whether or not afm cutout affects it or not. Would I ant that disabled? Though old school and wanting my own control, probably ABS is best to keep. Does this ever end? For a mixture of power vs longevity, especially the tranny, what are the best total changes to do with a new tune? Ill try to find a forum category for that.

 

[Marky Dissod]

After going through all the AFM posts, Ive decided there is such mixed opinion that it makes it hard to decide what to do.

Too many who don't fully get what's been going on with Engine Half@$$ since the late naughties are mixing their schidty opinions in with real wisdom.

Disable V4 mode as soon as practical - even using the shifter in M5 will disable it temporarily (read the manual already).
A plug-in that disables V4 mode, or even a plug-in with a 'canned tune-uh' in it, will never cover everything that a thorough tune covers.

A tune loaded from a laptop written by a tuner that has asked you about how you drive will always be better than an off-the-shelf tune,
even if you don't immediately see the thorough tune's benefits ...

 

[Joseph Garcia]

Decision time for you. Sh**, or get off the pot.

 

[Fless]

Analysis paralysis

 

[intheburbs]

I did it the easy way. I avoided AFM entirely. If either of my trucks die, I'll buy non-AFM replacements.
Either a 3500HD Suburban or a 6.4 Ram 2500.

 

[mikez71]

No, AFM disable DOES NOT disable ABS...

You may want to disable ABS for slippery offroad conditions and drifting competitions...

Decision time for you. Sh**, or get off the pot.

We need ^this^ more! But I mean some other threads, sounds like Marv has decided on a plug-in for now...

That forum you want, one of them is https://forum.hptuners.com/forum.php

Your questions about shift speeds and torque converter control will depend on how/what/where you drive.
Generally, everybody disables TCC lockup in 1-3 or 1-4, bumps 5&6 shift speeds.
Many reduce or zero the slip, speed up shift times, and bump shift pressures.
I found myself lowering my part throttle shift speeds for smoother shifting with the TCC disengaged.

 

[fredcook]

I've been in the "I'll deal with AFM when it fails" camp. Thing is, over the life of three Tahoe's (two of which i still own), I have yet to experience failed AFM. So my "when" has turned into "if". I put just over 300,000 miles on the 1st Tahoe, and the last I heard, the new owner has added another 75,000. No AFM issues. The two I still own, one at ~150k, the other over 260k, are also AFM issue free. All are 5.3 Flex. The only thing I can identify as different from my AFM trouble free experience to the (only) 2 people I personally know that had AFM issues, is I religiously stick to Mobil synthetic 5W30 oil. The two others that had failures with their 5.3's went with something else for oil. BTW, I change my oil when the DIC says it's time... no sooner, no later, regardless of how many miles it's been. In fact, I don't even know how many miles I get between DIC messages. I'm not saying that's the reason I haven't experienced AFM fails, but it's the only difference I can see between how I maintain mine versus the other two. But then again, while there are many AFM failures, there are still many, many more that don't fail. I guess I just happen to be in that no fail bucket...

 

[Marky Dissod]

If you do enough AI 'research', or you bother to ask enough of those like us, you'll find that your best bet - which is NOT a guarantee -
is to use a Group4 'full synthetic' 0w30 or 5w30 motor oil, and change it sooner / more often than the Oil Life Monitor says to.
Valvoline Restore & Protect 5W30 became my favorite after my mechanic asked me if I'd bought a new dipstick; I didn't.

 

[MarvinVR]

Wow wasnt expecting the hostility. Its a subject about which I know nothing and wanted opinons. Ive hardly become constipated over it. Mikesz71---thank you for a good and civil answer. I dont think I want to be in this forum any longer