RA003 Active Fuel Management Disabler Device, AFM/DFM Disabler Device Compatible with most GM V6 and V8 Vehicles

I received this today and couldn’t wait to try it. My 2007 Chevrolet Tahoe has the AFM. Recently it developed a “shuddering” in the engine when slowing down, along with a little feel of a periodic misfire at idle. My mechanic discovered the misfire was occurring in cylinder 4 and was likely related to the shuddering and these were both caused by AFM. Installing is a breeze. However, I did not disconnect the battery as the instructions indicate, but had read other reviews stating they just plugged it in while the engine was off, so I did that. The unit went through a cycle with the lights and then settled on one light on at the end. I let the car sit for several hours as I had some other business to attend to. I then hopped in the tahoe and it fired right up, and took it for a drive. It performed excellent. Love the feel of the V8 all the time. Shuddering completely gone with no V4 at any time throughout the ride. I still felt a little periodic misfire at idle, but that’s likely a lifter that is sticking a bit. My only regret is that I didn’t plug this in at 100,001 miles as I believe the lifter sticking (which is the beginning of the end for the motor) is due to AFM. I currently have just over 200,000 miles on the car and engine and with this device I just might make 300,000. If you’re looking for an AFM Disabler, this is a solid pick at a good price! Let’s see how it does over time….

Bought this for a 2015 GMC Yukon XL. The Yukon was sluggish in 4 cylinder mode and did not transition smoothly between 4 and 8 cylinders. We were also having torque converter issues and needed to be able to tell which symptoms were from torque converter issues and which symptoms were just transition between 4 and 8 cylinders. Turns out a new torque converter was needed, but left this plugged in simply for in town driving because of the lugging. So far a slight decrease in mpg has been noticed, but well worth it for nice smooth in town driving. It is also nice on the highway to not have to wait for the truck to switch modes then downshift for acceleration. Would definitely recommend! This seems to do just as good of a job as any other brand would for much less money. Bought this one because of the good reviews and wanted to share that it has been well worth it! Hoping to also save the hassle of doing lifters in the future.

Works great. The blue light lets you know it is connected and when it is off it Not draining the battery. I left it plugged in for a week with no drainage issues to the battery. I definitely recommend if you want V8 power all the time. Mine is used in a 2010 Avalanche Z71 with flex fuel.

I had all the DOD headaches! So I removed the DOD camshaft, lifters, oil feed manifold and plugged all oil galleys that fed the lifters. My engine ran great! However, the ecu on this model cannot be programmed to turn off the DOD. The problem this causes is that the ecu turns off the injectors to the four cylinders when it calls for 4 cyl mode! I was concerned about buying this disabler because although I didn't want the 4 cyl mode to kick in, I DID want the auto stop feature to work. This unit works great! No DOD request from the ecu AND the auto stop feature works perfectly. I am currently getting 19.5 miles per gallon. Don't be afraid of buying it. I've been using it a month now with no problems. Update, I bought it in March 2024 it's now December 2025. Still working great almost two years now!

Just arrive this morning so this is a "Day 1" review. Plugged the device in, took the pickup out for a 30 minute cruise where I know it would attempt to go into V4 mode in multiple conditions. No problem, it stayed in V8 mode 100% of the time. Simple no frills instructions/packaging when it arrived. I purchased mainly to get rid of that annoying fluttering/stuttering when my 2010 Silverado goes from V4 back into V8 mode. If it helps with oil consumption as some mention, bonus. Not super concerned if it has minimal fuel mileage effects... I used to own a Range brand in another pickup that worked fine but forgot to pull it from the diagnostics port when I sold it. Thought I'd save $60 or so and purchase this brand. LED lights on the Range were annoying to me (at night) as are the lights on this one, so I'll eventually put a piece of electrical tape over the lights for out of sight/out of mind. If my experience changes with this, I will come back & update this review. 11/4/20 Update: Changed my rating from 5 to 4 stars because of the assembly quality, plus I've added a 2nd picture of the unit in 2 pcs because it came apart on me when I was removing it from the diagnostics port. I pulled on the device while plugged in & the cover/front case came off and left the plug & circuit board still in the diagnostics port. Not cool, could have easily damaged the circuit board if I wasn't paying attention. These 2 pcs snapped back together and you have to be careful where you grip when unplugging else you'll wind up with 2 pcs. They have cheap little plastic tabs to hold them together (poorly) and after putting them back together, I plugged it back in and it worked fine yet. Just be careful where you grip when when you unplug it. 4/28/25 Update: Still working like a charm. Out of sight, out of mind. Not a single hiccup in 4.5 yrs...

It’s only been on for a 20 minute drive, but so far I am extremely happy and it has done exactly what it says it does. I have it on my 2009/10 Australian Holden Commodore 6.0 litre VE SS Ute, and it has stayed on 8 cylinders. I was a little hesitant because there were no reviews from Australia, but I received an answer to a question I asked from a fellow Aussie and that gave me the confidence to go ahead. Delivery was pretty quick too, arriving in half the time it was expected. EDIT February 2022: still working well!

My 2018 Silverado as never ran so good, clean responsive and shifts smooth. It actually feels like the 327cu. I thought I bought. Money well spent and I no longer have to run it in manual to keep it in V-8 But here we are only one year later and this thing has messed my truck up so bad . NOT impressed

I'm so happy with this product so far. I've only had it a week, but it works 100%. Installation was easy. Instructions say to disconnect battery, but I didn't (I'm getting lazy in my old age). It worked with no problems whatsoever. 8 Cylinders all the time now. I'm very pleased. I'm not sure as it's to early to tell, but it seems to be giving me better gas mileage...could this even be possible?! I don't know, but will edit this review in the future to keep you posted on it's longevity & overall results. It just feels like my truck is running better....maybe it's all in my head, but I'm happy so far.

I've had it in my 2018 Silverado for 3 months now, and it performing as advertised. It has decreased my fuel consumption by approximately 2L/100kms as well.

Super easy to use. Just plug it in and drive. Works perfectly. Plugged it in and haven’t had V4 kick in since!!