DK Custom Products

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FL-ViED Fuel Enrichment for Harley EFI Plug-n-Play..More Details

Availability: In stock
Item #: DK-FLVIED-10-NR
Manufacturer: DK Custom Products

Dyno Chart for Plug-n-Play Fuel Enrichment for Fuel Injected Harley-Davidsons FL-ViED-10 Lowers Engine & Exhaust Temps - Improves Throttle Response Harley-Davidson DK Custom

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Dynamic Tuning For Harley-Davidson Motorcycles
Variable Inline Enrichment Device


A Cost Effective Alternative to an Aftermarket Tuner & Dyno Runs.

This Patented Device Dynamically Adjusts to Changes Made to Your Bike!

FL-ViED-10's will Cool Your Bike Down & Make it Run Better!


The Patented Plug-n-Play FL-ViED-10 richens the Air Fuel Ratio from14.6:1 to a range of 14.3-13.9:1 in closed loop mode.  

This Variable Fuel management upgrade allows you to fine-tune the air fuel mixture with a small screwdriver.

Immediate Benefits:

  • Lower Engine Temperature
  • Lower Exhaust Temperature
  • Improved Throttle Response
  • Reduced Surging
  • Reduced Pinging




  • Touring/Trikes 2010-2016 (including the Twin-Cooled Models)
  • Softail  2012-2017
  • Dyna  2012-2017
  • V-Rod  2012-2016

Recommended for: Stock Bikes, & Stage I Bikes (High Flow Intake & Exhaust) Will NOT Work with Stage II, III, or IV.

Note:  It is recommended that bikes that have full exhaust system upgrades, or those with the catalytic converter removed, use this FL-ViED-10 product.  Fine tuning of the O2 sensor signals may be required to optimize the fuel mixture when the catalytic converter is not in place.


Simple install-comes with instructions.  No tools required, installs in a few minutes.


They work inline with the smaller H-D Delphi heated narrow band 02 sensors and Delphi ECM to richen the fuel mixtures, adding up to 6% more fuel to the engine in closed loop mode.

There is an indirect richening of the open loop fuel mixtures through the learning mode, or adaptive fuel value action built into your ECM.  This ensures the richer 13.8-12.5:1 AFR's are ALSO adjusted in heavy/full throttle operation.

LINK to All Dynamic Tuners 

"The 'too lean' hesitation at start off was gone. Also gone was the decal popping. Using my highly calibrated dyno-ass I could feel a tad more pull at low end.  

Overall I'm happy. So happy that I'll be ordering another set for wife's '14 Tri-Glide" -Screwball


"409” ignition wires provide continuous heat protection up to 600-degrees Fahrenheit

Posted by Stephen P Mullen on 10/1/2009 to HD Tech Notes


What do the 131/151 codes mean?
The codes are specifically listed as P0131 and P0151 codes. The description in the Service Manual is:
P0131    Front O2 sensor low or engine running lean
P0151    Rear O2 sensor low or engine running lean
The key point to look at here is "O2 sensor low" when analyzing what is happening with the XIED's in place. The O2 sensor produces a 0.0 to 1.0 Volt output. Any voltage lower than a preset threshold in the ECM can trigger the 131/151 errors. Lower voltage equates to a leaner fuel mixture in the eyes of the ECM. The XIED's take a higher voltage from the O2 sensor and "shift" it to a lower voltage for the ECM to read. In some circumstances, the ECM will see this low voltage as "too low" and trigger the code despite the fact that the engine is running rich enough. The IED's take advantage of this voltage shift to richen the mixture.
So the engine can be running rich and the ECM might still trigger the "sensor low" signal.
There are also other reasons that the ECM will trigger the codes that we will try to cover below.

Will these codes hurt my bike?
No. These are historic codes and are not active. As long as these are the only engine codes you have and you do not have an active Check Engine light on, they can be safely ignored.

Do all bikes get these codes with IED's installed?
No. Many bikes never see these codes. You could also have the codes and never know it. Unless you check the historical codes on your bike, you might never see these.

Do completely stock bikes get these errors?
 Completely stock bikes get these 131/151 errors on a regular basis as evidence that Harley has included a note to "clear and ignore" these codes in their Service Manual.

Don't historical codes mean there is a problem?
No. Historical codes only mean the ECM saw something it did not expect. If the code is considered a potential problem or there is a risk of damage to the engine, the ECM will turn on the Check Engine light. No such situation exists with the 131/151 codes. The Harley Service Manual actually notes that these codes should be "cleared and ignored".

I have read that these codes cause the ECM to revert back to open loop mode. Is this true?
No. The ECM will only revert to open loop operation if there is an active error code. Active error codes will cause the Check Engine light to come on. As long as you have no CE light, your bike will run in closed loop for normal riding situations.

When I take the XiED's off my bike, the codes go away. Doesn't this prove the XiED's are creating the problem?
No. It can be easy to confuse the installation of the IED's as the cause of the error. This is a normal reaction and quite understandable for the average rider. In engineering circles there is something known as "root cause" analysis. The "trigger" mechanism is not always the cause of a problem. In this case, the "trigger" is the IED's. The IED's do make the ECM more prone to showing these codes, but there are a host of issues that cause the codes. Harley has documented many of these causes in their Service Manuals. A copy of the specific section of the Service Manual is listed below.

Are there other things that can cause the error codes?
Yes. We have information from an EPA testing laboratory that there are several other issues associated with these codes. These are engineering issues that are deeply embedded into the HD Delphi ECM. Our information also indicates that Harley is aware of these issues, but does not have plans to create any upgrades to eliminate know problems.

Can you get rid of the 131/151 codes?
 It is important that a rider ensure that they have eliminated the common reasons for triggering the codes with the IED's installed. The primary triggers are exhaust leaks and loose O2 sensors. Even the smallest exhaust leak can trigger the codes. We have found that many of the bikes that have codes will get rid of them when they carefully check their exhaust system.

Can I just run my bike with the codes and not worry?
As long as you do not get an active check engine light, you can run your bike with the IED's. For any active check engine light, you want to have that checked to find out what is setting off the CE light.

Customer Reviews

FL-VIED Review by Mongo7
Bought these for my basically stock 2016 Street Bob as an interim to help performance and longevity until mods are done and I’m ready for a tuner.
Immediately on startup the bike idled better and throttle response seemed to improve. Took a couple of rides to find the sweet spot, and I am happy with the results. (Posted on 3/21/2023)
It works Review by Did not disappoint
I installed this on my 2015 Electra Glide. I have been riding this particular bike for about 6 years and noticed the difference after the first ride and parameter reset process. Knowing this bike helped me to notice the definite difference in idle and throttle response. No more hesitation at any speed, in any gear. I cannot say with certainly that my bike is running any cooler, but this product has done everything else as advertised so I am going on faith to say it does. (Posted on 11/2/2022)
Excellent Product Review by Steampunk
I installed the FL-VIED-10 on my wife's 2014 Heritage Softail. The bike was bone stock and she wanted some music from her exhaust. I bought an exhaust and air cleaner for her bike, but it was running fairly hot already. I had installed a crotch cooler for her to ameliorate some of the engine heat, but I knew that wouldn't help out the motor. After a lot of investigation, I chose this DK Custom product. Easy installation, truly plug-and-play. My wife couldn't believe the seat-of-the-pants (literally) difference. It may have added a little oomph to her bike, but she doesn't care about that, she just didn't want to fry her leg, and it was a distraction. Now her attention is on her riding and not the excessive engine heat. Thanks guys, amazing product. (Posted on 7/20/2022)
go ahead and get them Review by jim
2013 ultra, worked great, brought down the engine temp and boosted performance. (Posted on 6/24/2022)
Works Great, As Advertised Review by X-Airborne
‘11 Ultra Limited, K&N Air Filter w/ Stock Airbox, Stock Header, Slip-on Mufflers. I was skeptical of the FL-VIED-10 being able to do everything they claimed, but it works great. The terrible ping-ping under load completely went away and the cylinder temps are noticeably cooler on my well-calibrated thermal sensing right leg. Better low-end response when starting from a stop. Super easy install, took me 10 minutes. I started out with it set to ~55%; it cooled the cylinder temps significantly but I still had some light pinging at high speeds. I upped it to ~70% and the pinging is completely gone. No check engine light, no downside that I’ve yet seen at 500+ miles after install. (Posted on 5/30/2022)
Great product with great results Review by Roadglider
I purchased the FL- ViED to great a richer running and cooler running bike. It took about 20 minutes to install and was easy plug and play. The bike is running great and alot cooler than stock settings. I noticed a definite power increase and throttle response. Now to see how long she'll last. Very satisfied! (Posted on 10/11/2021)
FL VIED's do what they say Review by Daniel
I was familiar with the night rider products from being a former BMW owner. I knew that they were a good solution for lean running machines. They work great on my FLHCTU to lessen the heat output and reduce the decel popping. I could tell a difference on the first start up as it idled a bit faster. The first ride did show an improvement in throttle response and power. Definitely satisfied, as they did exactly what I was expecting. (Posted on 9/21/2021)
Awesomeness!! Review by Dave U.
First of all should say I am very new owner of a 15 TriGlide. After I bought the trike I started reading about how to maintain and what to check and look for as I wanted to be prepared for common concerns. Once I started reading about how lean these run I wanted to find a solution. After hours and hours of reading and research I decided to give these a try. Coming from the car world I know the problems running lean can do. I had several questions called them directly and got all of them answered. I love the fact that I was talked to like a person and not just another sale. I was not looking for more power just a properly running machine. My trike runs awesome and is definitely more responsive. I am beyond thrilled with the results. I also love all the videos that are online to watch and learn. All in all it was the honest videos and no BS proof with the results provided. Thanks again for awesome service and products. (Posted on 8/20/2021)
5 star Review by Widetrack
Added just enough power to be noticed. Fuel mileage has gone up also. Idles smother (Posted on 7/27/2021)
Good stuff all around Review by Sly
It works (Posted on 7/14/2021)
Great product Review by Tj
Noticeable difference bike runs better and seems to run cooler would recommend (Posted on 6/29/2021)
Perfect! Review by Lance G
'10 Ultra Limited, completely stock except for 4" RCX slip-ons and de-catted header pipe. It didn't run right after de-catting...idled rough, laggy low-end power, and surged/lagged at mid-throttle. After installing DK's FL-VIED-10 and dialing to about 35%, it runs beautifully now. Idle is perfect, no more low-end lag, and no more mid-throttle surge/lag. Feels like it's pulling a little harder too. 10 minutes to install, and 100% satisfied with results! Thanks DK! (Posted on 6/17/2021)
A+ product Review by Trikerster
I have used Night Rider in the past, good quality, and product does what it says it does. Would recommend. (Posted on 2/25/2021)
DK-FLVIED-10-NR Review by Al Corr
Very easy to install, just Plug-n-Play. Enrichment for Fuel Injected Harley-Davidsons. Lowers Engine Temps. Improves Throttle Response. (Posted on 10/31/2020)
FL-ViED-10 Review by Pastor
First installed on our 15 FLHR and noticed incredible improvement first time ridden. Gone was the low end surging in first gear and the exhaust was much cooler on the highway. Then we ordered a kit for our 16 FLSTC that has always run hot enough to make the freeway ride uncomfortable. Same result, no surging, and the heat was gone. The engine on both machines just seems happier now. Very happy with the product, I only question why the manufacture only offers a 30 day warranty on this kit. (Posted on 9/9/2020)
$$ well spent Review by PJ
Super easy install. Cleaned up all the lean hesitation, and engine just seems generally happier, as well as pulling harder.
Have the same unit on my BMW R1200GSA, with similar results. (Posted on 7/17/2020)
Well worth the money Review by Rod
I put this on my 2016 Electra Glide, the only mods i have are slip on mufflers. This definitely improved the low rpm lean stumble. i also think it runs better over all. doesn't make it a race bike and that's not what i was after, but i do think it is well worth the money unless you want to spend big bucks getting a dyno tune. (Posted on 5/20/2020)
Product/customer service review Review by Joe
This product is an easy plug and play, it does what it advertises that it will do, DK customer service is some of the best I have dealt with, we had a small issue that was dealt with expeditiously and with courtesy, I would recommend both (Posted on 7/25/2019)
Product review Review by Joe Joe
The FL-VIED wires that I bought are too easy to install, the improvement that I have really noticed is the increase in my take off torque, (I have the wires set at 50% or half), I will set it to 60% just to see what or how it responds, I would recommend this product. Price is reasonable for what it does (Posted on 7/22/2019)
Well worth the reasonable cost Review by T103
Easy install. Very good instructions for installation and use. I’ve used them on other bikes and they definitely smooth the throttle operation and help enrich the fuel mixture. (Posted on 6/12/2019)

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