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

I am so happy with this thing that I actually could not wait to do this review. Having my 2015 Silverado 1500 Z71 with 5.3 engine for more than a year now, this AFM disabler is the best thing I have done to it. Like many others, at first I thought the AFM function was fairly neat. A way to save a bit of fuel. But, although it is a consideration, do we really buy V8 trucks to go into 4-cylinder mode?As many others have suggested, including the manufacturer’s instructions, I didn’t plug this thing in until I first disconnected my negative terminal from the battery. After that, one push into the OBD port and then reconnect the battery. Took all of 15 seconds. Don’t be put off by the simple packaging and one-page instruction sheet. That is all you need. I let it stop flashing and proceeded to take s test drive.Highway speed or moderate to heavy acceleration was never the problem. My complaint was the transition to 4-cylinder as I drove through the 20mph areas where I live or when gently trying to accelerate after a near stop for a traffic light. That is when the AFM made that annoying pop from the exhaust, custom run duals behind the passenger side rear wheel, and there was a delay in acceleration. No longer! It was immediately better. Drove the same street where it ALWAYS went into half-engine mode but this time the display indicated the V8 was always active. It kept the throaty sound and actually pushed better at slow speeds before I needed a heavier acceleration. As I stated previously, I instantly felt a difference.Now, for the skeptic. I was so very close to getting the Range AFM many times but could never quite bring myself to spend the $190 or so on what I thought was a “maybe it will work” situation. I found this one and, after reading many of the reviews, decided to try it knowing I would return it if it did not work and then buy the more expensive one. I don’t care what it’s branded. I only care that it was approximately $60 cheaper than any other one and that it works exactly as it should.If it fails, I will update this review. For now, though, I am very pleased and will tell anyone that it was the most quickly apparent improvement short of a custom program job or a new set of lifters, cam shaft etc. for my performance. Take it or leave the blue light glow on my foot well. I don’t really care for it so will probably put tape over the LEDs.

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….

The module is simple to install,just follow directions,the blue light goes off when the key is turned off so I don’t see no battery drain issues .My 2016 Silverado with the 5.3 ran excellent before the module but seems even better now shifting is smooth as silk ,oil pressure runs at 40 transmission still runs same temp all V8 mode no more 4 cylinder foolishness,I’m a vehicle enthusiast and very picky about my truck ,pull the trigger and get this module it could save you thousands in repairs in the long run 👍

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...