Fed up with the L99 and AFM

[MrE]

Originally Posted by rolnslo

Did you check with the service department to see if GM has a provision to maintain the powertrain warranty but let the dealership disable AFM for you? Might be worth a shot before losing money on the trade...

Problem is, if the dealership offered the ability to tune AFM out, there would be a line a mile long.

[MaroSS]

Turned off my AFM and im a happy camper! lol

[5thGenOwner]

Originally Posted by MrE

Problem is, if the dealership offered the ability to tune AFM out, there would be a line a mile long.

And an IRS agent at the front of it collecting his Gas Guzzler Tax!

[SoTHavok]

i have yet to notice what any of this sound is, probly cause im also bumpn tunes and i dont have stock exhaust hahaha ill listen for it now

[youngoliver]

i dont hear this either:/

[axis]

Originally Posted by ravensjeff

Expensive lesson. I'll deactivate afm and put on a tune, among other things, when the supercharger is installed. Also comes with a 3yr 36,000 mile warranty.

You might want to read the fine print on the SC warranty. Those "among other things" will probably void it's warranty as well. You have to run the original pulley, OEM exhaust, completely stock engine, and supplied tune. Anything other than that will void it.

[JoshJ81]

The AFM sound with stock exhaust is slightly noticeable IMO. However, it can be like that little annoying gnat that keeps flying around your head during that awesome weekend BBQ. The sound that it makes is like a buzzing sound when kicked in. But once you put some throttle on, it goes away cause all 8 cyclinders are kicked in. The problem in my mind is it just kicks on and off way to much.

The other problem is if you remove the resonator section (big box directly under the driver's seat under the car), the buzzing/drone will become even more apparent. I think if you remove any one of the 4 exhaust parts (manifolds for headers, stock cats for high flow cats, resonator removed for Xpipe, or stock mufflers for aftermarket mufflers) you'll hear this buzzing in some form.

I have not tried just changing the mufflers (looking at Flowmasters) but I would think just a muffler change would be the least difference. Just my opinion and I've not tried it.

A Diabo tuner chip turns off the AFM for you, among other goodies. But the best part, if you ever need to go to the dealer and fear a tune will ruin your warrenty, you can remove the chip and your computer will change back to stock maps (AKA turning AFM back on). I'm considering this as I'm looking into more stuff that will require my AFM turned off.

Good Luck but I urge you to looking into work arounds before taking a dump on your wallet. Unless you are just a staright up rich dude and money is not a problem.

[trudawg660]

Originally Posted by 5thGenOwner

And an IRS agent at the front of it collecting his Gas Guzzler Tax!

without AFM you still are no where close to getting the gas guzzler tax. i dont know why gm put it there in the first place. i guess it looked good on paper and to the people that think they are saying gas. the people that tuned it out say they lost 1 mpg

[wullger]

Have you tried driving around in S mode all the time? It doesn't eliminate the noise, but I -seem- to experience AFM kicking in less based on the areas/speeds that I usually drive.

[JoshJ81]

Originally Posted by wullger

Have you tried driving around in S mode all the time? It doesn't eliminate the noise, but I -seem- to experience AFM kicking in less based on the areas/speeds that I usually drive.

It doesn't matter what mode you are in, if the computer see that the engine's RPM is sustained at a certain number for a period of time, the AFM kicks on. There is no way to avoid AFM coming on short of a tuning it out by a tuner.

[wullger]

Notice I said -seem-? The shift points are a little different in Sport mode. Based on how I drive, it seems (again, seems--read the post this time) to have less occasion to kick in to AFM. Was curious if the OP has experienced this, to see if it might help him.

[JoshJ81]

umm ok...

[mlee]

Originally Posted by axis

You might want to read the fine print on the SC warranty. Those "among other things" will probably void it's warranty as well. You have to run the original pulley, OEM exhaust, completely stock engine, and supplied tune. Anything other than that will void it.

that's a worthless 3/36 warranty for sure.

If you're going to get aftermarket exhaust with the L99 consider one of the companies that offer an x-pipe w/ resonator or just go axle back. I beleve Magnaflow has a new one out.

Also if you tune out AFM you can do it gear by gear. I turned mine off in all gears except when in "D" 5th & 6th gear only. That way I get the best of both worlds....

[songsj]

I'm hoping GM will figure out a way to up the mileage and gas the AFM.
The whole idea of it on a muscle car just doesn't seem right however I think an auto should be available.