How to fix AFM misfire on 5.3 Chevy 

This guy deserves a Nobel peace prize!

This is good info. AFM - will go down in history as one of the stupidest ideas that GM has come up with. Best thing I ever did was stick a range technologies AFM delete into the obd port on my 2011 5.3.

06 Avalanche was doing this...unplugged the brake sensor and it absolutely worked....Thanks for sharing this hack!!

This was soooo helpful! I was having the EXACT same problem on the EXACT same cylinder! Mine is an 07 Avalanche so the sensor location was different but it still worked! My local garage that I've trusted for years wanted $3,000 to replace both heads and valves along with gaskets and labor. But after unplugging that sensor it ran fine and would still use the V8 and 4 cylinder modes! After a week and a half I decided to plug the sensor back in for the heck of it and it's STILL running great and getting the same mpg that I was before the problem started! Thank you sooo much again!

Thanks for this. My Buddy is currently having this misfire problem. 👍

Excellent! I too would take this option and top it off with a small piece of black tape over the check engine light…

Very helpful. Same problem just on cylinder 6. Thanks 👍

Hey man I dont ever leave comments on anything but you really helped me out. My 09 avalanche has been a beast. I thought for sure at 270k it needed a new motor when I got p0306. Watched this video and my truck is running like a champ

Another simple fix is on your gear selector, switching it to M5. It will keep you in v8 mode all of the time without much compromise, the only annoying thing about it is having to do it every time you drive the vehicle.

Unreal! Was gearing up ready to order lifters etc etc etc. 👍🏼

Thanks I'm going to try this. I have this problem on #1.

You sir...deserve this 👑

I'm literally about to get bundled up and go out in this snow and this 15 degree temperature to see if this fixes my issue. If i wanted a 4 cylinder i would have got one. Thanks man

Wow that is way to easy, great video.

Hey man I can't thank you enough I been dealing with this after replacing everything you are the man

This works. It fixed my 2007 Silverado

Really. Hoping this helps me got. A 07 5.3l. Tahoe. And. Just few days ago. Starting knocking. Etc. going through gas. And bad acceleration. Been trying oil stabilization and mystery oil in the gas. And. It’s helps. Some. But. Ima try this !

A Gold Nugget, Great info. Much appreciated.

Have a 2011 5.3 Silverado. I tried an AFM DISABLER, it worked sort of for a week then back to shuddering. I'm going to try this now.

Tow/Haul button will also keep it full v-8, only drawback is remote start will NOT work while the check engine light is on, not a big deal though if you don't use it much.

thanks, this was money saving video !

Didn’t try it yet but regardless, excellent information buddy. Thanks

Thanks for posting, but I disabled the AFM on my 2013 Silverado with a box you plug into the ecm. It just started missing badly. what now?

Amazing video bro....thanks

I would have thought that even though you were able to disable the AFM, that the lifter would have still been stuck. Apparently, it was able to unstuck itself after you disabled AFM. I just ordered a Range module to disable my AFM, so hopefully, I'll avoid the stuck lifter problem and not have a check engine light staring me in the face. The issue I could see with having your check engine light on after your fix, is that if something else were to go wrong with the engine you wouldn't know it, since your check engine light is already on.

This Should Be A Factory Recall!!!

Thanks for sharing this information. You tubers I recommend you speed the video up. Southern folk do speak slow 😅. Thanks again!

Gracias, A'm going to try !! Gracias , Gracias !!

Still getting that pulse feeling should I try and clear the codes after

Hi! My 2012 was giving a misfire code as well. I change the spark plugs thinking that will fix it. Now when I drive it kind of rattles or feels like it wants to stop. I don’t have an engine light on and the oils and temp are normal

Would it be cheaper just to get another 5.3 I have hella codes and it’s ticking and I have white smoke coming put

This is a temporary fix, these engines come with a high volume oil pump to collapse the lifters and you can disable the system with a tuner as well, but eventually when the lifters permanently collapse your engine will start to bog down randomly and oil will bleed into the intake and cylinder walls, because the afm mechanical parts are still in the engine and you will get random misfires on those certain cylinders plus the camshaft will still try to activate/deactivate those cylinders because it's still physically in the engine. I took my intake off after having oil seep into 2 of those 4 cylinders and my intake had literally 2 quarts of oil in it

Thank u my friend!!

Would this work on the 07 Tahoe LS flex fuel

I have an 07 Silverado 6.0 with lifter 8 fck’d What should I do with it?

What was the oil psi before did this? Was it 0 are did it fluctuate. Thanks

But what if the lifter is already tapping will it work then

I tried this is my 2011 Chevy Silverado with 5.3 and it didn’t work for me. Maybe on some models ? Or for some other reason ?

I have a question. I have a 2008 Suburban 5.3 and I want to prevent the problems that arise from the AFM & DOD. If I replace the valve cover with the new baffle and then do the tune to the ECM would that prevent the engine light from coming on? Thanks for your hard making this video...

I have one of these and the check engine light comes on until you start the engine and then it goes out and it stays in V8 mode all the time and runs fine

Do you know what could cause vibrations when engine goes to V4 mode? Lifters not stucked, afm works but i feel bad vibrations. With Range OBD device everything is ok. No fault codes, no knocking sounds. 2011 chevrolet camaro ss L99 engine

Will this work on a 2005 Chevy avalanche

i have a 2010 chevy tahoe hybrid, where is this AFM sensor to disconnect it?

So i am throwing the p9306/300 and it specifically ssys its cylinder 6 misfire. Changed the spark plugs my next go to is tbd coils and wires im reslky thinking that is the issue with the behaviir of the truck. Does this hack apply to the cylinder 6 misfire also?

Well done sir! I am looking at buying a 2006 Envoy Denali . Is their a definitive way to tell if I have DOD or AFM on the 5.3L? I have searched the net , forums & found yours on YT. (But with varying answers) Is it in the VIN#,?Or Tell by the valley plate? the owners manual does not even mention it. they say they get worst with age.If it was newer I would use your technique . But they say at the age of the SUV its not a question if its when. take care & best regards.

Will this work on a 2014 silverador

I'm looking at a 2004 Buick Renier 5.3 that has a cylinder 8 misfire i hope it's just a spark plug issue

sir can i unplug afm soket no problem ??

does this work. for cilinder 5?

Would it work on a 07 Silverado 5.3 ?

I have v8 Colorado factory 5.3 it don’t have 4 cylinder mode

Was your misfire just random shaking at a red light? No issues under load.

Deleted AFM program. wire wheeled all exterior grounds. including one under dash cover. (costs nothing) started back up with 5-30 Amsoil signature /3500 max oil change. Using 5x detergent gas. Flawless performance. More pep. shifts stronger. 1.5 MPG more. But most important: no more codes on dash ! Stock except for MSD copper core plug wires. 2014 Silverado 4.3 V-6, 83K.

My 2015 Yukon Denali is currently in the shop having all the lifters replaced. I have one of those Range AFM Disabler that I'm going to use when I get my vehicle back. What is that test set? Are they expensive? I would love to look at the codes and alarms in my system.

Hey i dont have that break booster in my 08 silverado. Any other sensor this may work with that isnt a big deal?

I have a 2015 4.3 liter V6 chevy silverado 1500wt, will this work? Also, my lifter is stuck and no compression on cylinder 6, do I need to pop the head and replace the lifter first?

Sorry if this a dumb question once the lifter is not collapsed can u just plug it bk in and work ?

Will it work 2002 Silverado

I have an 04 Tahoe 5.3 flex and I have code p0300 put in new engine and still getting the same code

Will this hack work on a 2015 Silverado 5.3

May 5th 10:00 pm do u have to clear the codes. I unplugged mine on a 2008 Silverado and it didn’t change anything. My code is misfire on cyl 7. Have to undo battery or anything like that

Wonder if it work for 6.2

Did you have to unstuck the lifter first

U R a genius....

I'm dropping everything and running to try this now

How you unplug this sensor

If you watch your inst economy even with the brake booster sensor off it will still go to 4cyl when u release the pedal. I've done tow haul mode and still drops to 4. Last resort was drive in 3rd my gear and like that is the only absolute way to not drop cylinders until you're ready to fix it delete DOD

Does this work on the 6.2?

hello what happens if you use a cheap scan tool to deactivate AFM? will it fix this issue also or not really?

The 2012 model is different, the sensor is not in the same location and when un plugged the service brakes, service abs all come on. So not the same for a 2012

does this work for 2011 gmc sierra?

Hi. Did you have any smoke coming out of your exhaust when you experienced the misfire in your cylinder 4?

So did you have to un stick the lifter before you Unplugged the sensor?

I have bad lifter #6 that can help me

Excelente👏👍👍

Is this prior to getting the tick or does this hack potentially work after you get the tick?

Hey man o4 tahoe doesn't have that sensor and I replaced everything you did so what can I do

respect. thank you

Thank you so much.....

On another video a guy just replaced the map sensor right there on top of the manifold and that fix the misfire you might want to try that also.

I been dealing with traction control and engine light popping up and the truck starts shaking but I will be trying this

I have a Toyota Camry 2001 2.2 Liter engine 4 Cyl . I have this kinda problem. After changing my Spark Plugs and New wires and New Coil wires .It still Misfires. Then I change my Fuel Injectors Change Oil and put some Lucas Fuel Injector cleaner Still Misfires . This is the Codes that is Showing up P0300 Random /Multiple Cylinder Misfire P0301 Cylinder 1 Misfire P0302 Cylinder 2 Misfire P0303 Cylinder 3 Misfire Is this hack going to work on my vehicle ?

How did you get the stuck lifter to unstick, I had to get mine redone. To get it unstuck. And paid to have them. Delete the AFM

can I replace lifters only on one head ? do I need to replace camshaft ?

Didn't work for my 07 suburban musta mechanically failed.

Does unplugging that disable the ABS?

No audio???

So I tried this and it didn't help my issue now my service brakes soon light is staying on. :/

Hey I'm about to try and unplug the brake booster you described and see if it helps my 2003 tahoe 5.3 ls flex i just recently bought the car and so the problem i have with it is ill be driving and the car shuts off and ill have to put in neutral and try and start it as I'm rolling or I have to pull over and put in park and start it but it has a p0300 misfire cylinder 7

I have a 2008 silverado 5,3 I tried unplugging the brake sensor didnt do anything mine is misfire on cylinder # 1 im pretty sure that the lifter is stuck, if that lifter is mechanically stuck will it have to be un stuck before this would work

Thanks for the video. Was your vehicle smoking also?

Could this be the cause of my 2017 Tahoe 5.3 setting a P050D code which is "Cold Start-Rough Idle" ? After about 2 minutes, all is well until the next morning start up. The code is permanent. Thanks

How about the 2015 gmc 5.3

What if you have hydro boost 😢

I have a 2020 Silverado 5.3 misfire cylinder three.. so I’m assuming this hack won’t work?

Mine still went into v4 on dash, weather it actually did or not im not sure

AFM needs about 27 psi to activate. I have low oil pressure (probably the oil pan relief valve is bad) and rarely makes it to 27psi on the the highway so it never activates.

Can put tranny in M mode and gear in 5 and that inactivated AFM.

07 Sierra 1500 with the 5.3 Vortec. Yesterday got the misfire on 6 along with Stabiltrack and Traction Control lights. Terribly rough shifting and tapping. Anyone have these symptoms and have luck after disabling AFM?

i have misfire #6 ...no compression on that cylinder....didnt worked for me :(