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Tuning Done The Right Way

Dale (Misled) Hvizdo

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Your average biker that has a Harley usually adds some customization to the bike not leaving it stock very long. And if they are a gear head, usually the first thing they do is take off the stock exhaust and upgrade to something that is louder and throatier. With fuel injection you can make some minor changes to the exhaust or air cleaner but not both at the same time without the need for re-tuning the motorcycle. There are plenty of aftermarket solutions for this but if you’re like me riding a new motorcycle you will void your warranty if you do.
Harley Davidson offers a solution for this, they have their Screamin' Eagle Pro Street Tuner which meets 50 US states EPA emissions. It simply plugs into your motorcycle data port talking directly to the Engine Control Module (ECM) and reprograms the operating system on the motorcycle. It does not piggy back on the ECM like other aftermarket systems that try to fool the ECM by adding more fuel or changing the timing. By picking your motorcycle and proper hardware setup you get a map version that you upload the computer and have a decent starting point to be on your way. From there you could go to a shop and have your ride Dyno tuned and have your setup dialed in to be optimize. If you like to tinker and do things on your own the Vehicle Communications Interface (VCI) can record 15 minutes of run-time data to evaluate things like air/fuel ratio, O2 sensor readings, engine speed and temperature, RPM and vehicle speed, throttle position and spark advance. After evaluating the data the software gives the ability to adjust

They also have a great online tutorial explaining all the key components of the engine and electrical and fuel system and what starting points should look like and how to adjust and modify. You can find the free web-based training here:

The software offers a guided smart tune process to quickly navigate through whether you’re a new to tuning or experienced.

You can also record and view service codes for diagnostics and troubleshooting.

If you plan on riding the same elevation this is all you need. The system should allow you to go to other elevations but may not run optimized. If this is a concern Harley also offers an option for this, it is the Screamin' Eagle Smart Tune PRO Automatic Tuning Module (ATM). It automatically tunes your bike for the combination of performance components, temperatures, altitude, and vehicle load conditions you are operating in.

It constantly monitors the motorcycle and modifies the ECM on the fly to give maximum performance in most conditions. It is able to do this by the wideband O2 sensors it utilizes reading oxygen levels in the exhaust stream to determine the optimum air/fuel ratio, spark advance and timing your bike needs at the moment.

In order to take advantage of this option you do need to have the Screamin' Eagle Pro Street Tuner also. If you add this at a later date you do need to upload a new map with the selected wide band sensors. Then all you have to do is ride and enjoy.

Install is a straight forward procedure:

1.    Remove saddlebags

2.    Remove main fuse

3.    Remove seat.

4.    Remove battery


a.    Release ECM from top caddy. Move out of the way.

b.    If present, move purge solenoid forward to release from top caddy

c.    Models with security system: Release HFSM antenna from top caddy and move out of the way

d.    Release connectors from anchors on top caddy

e.    Remove fasteners

f.     Cut cable straps. Move harnesses to allow more clearance for the top caddy

g.    Push top caddy forward to disengage front of caddy from front hold-down bracket. Lift and remove top caddy

h.    Disconnect both battery cables, negative battery cable first.

i.      Pull up battery strap to raise battery. When battery is extracted far enough to get a good grip, grasp battery and remove


5.    Remove right front footboard and brackets from frame.

6.    Disconnect front and rear heated oxygen sensor (HO2) connectors

a.    Note routing of oxygen sensor harness and placement of cable straps along the frame

 Remove exhaust system.


8.    Rework exhaust pipe. Use Exhaust Oxygen Sensor (Wide Band HO2) Bung Drill And Tap Tool Kit (Part No. 14900105) to complete procedure or install Screamin Eagle High-Flow Exhaust System with Street Cannon Mufflers for HO2 sensor installation

a.    Note that no rework is required on Screamin Eagle High-Flow Exhaust System. Bungs accept wide band HO2 sensors.


9.    Install wide band heated oxygen sensors. Using Oxygen Sensor Socket (Part No. HD-48262-A) Torque: 40–60 N·m (29–44 ft-lbs)

a.    Do not install sensors that have been dropped or impacted by other components the sensing element may be damaged

b.    Replacement sensor assemblies have threads coated with anti-seize lubricant and a new gasket.


c.    The electrical connector must be clean and free of any dielectric grease.

10. Install exhaust system with new exhaust gaskets

a.    It is acceptable for the wide band sensor strain guide to make contact with the transmission cover.


b.    If there is contact between the O2 sensor body and transmission cover, install a couple of washers or a spacer under the mid-frame exhaust clamp. Up to 0.200 in of spacer is acceptable.


11. With the ATM inside the battery box, route grey and black connector harnesses

a.    Start at front right corner of battery box area.

b.    Slide grey or black connector harness (1) between the brake lines (2) and frame rail.

c.    Slide connector harness along until it exits the battery box area and enters side cover area.


d.    Repeat procedure for other connector harness.


12. Route the grey and black connector harness leads out behind the ABS control module and connect to main harness. Color match connectors: black to black and grey to grey.


13. Clean mounting surface with alcohol pad. Remove liner from adhesive backing and install dual lock tape to ATM. Remove liner from adhesive backing of dual lock tape and install ATM to back of battery compartment.


14. Install ATM with wire harness facing right toward the inboard side of the frame

15. Route and connect ATM ground wire to clean ground post and torque to 6–10 N·m (50–90 in-lbs)


16. Front HO2 sensor (long harness lead):

a.    From front sensor, route and secure O2 harness along the inboard side of the right frame downpipe. Install cable straps as needed.


b.    Route and secure harness along inboard side of the lower frame toward the O2 sensor connector. Install cable straps as needed or use existing clamps and retainers.


c.    Connect O2 sensor connectors.

17. Rear HO2 sensor (4, short harness lead):

a.    From rear sensor, route and secure O2 harness along top of transmission (4). Install cable straps as needed.


b.    From battery box area, route and secure ATM harness toward the O2 sensor connector. Secure with cable straps as needed.


c.    Connect O2 sensor connectors.

18. Make sure all harnesses and connectors are secured and not located in any hot zones.


19. Install right front footboard and brackets to frame

20. Install battery, battery caddy and attach ECM.

21.  Install seat. After installing seat, pull up on the seat to verify that it is secure.

22. Install main fuse.

23. Install saddlebags.


24. Use Screamin' Eagle Pro Street Tuner to complete installation. Download new ECM calibration when installing this kit.

When selecting a calibration to download with the Screamin Eagle Pro Street Tuner, select Wideband from the pull down menu for the O2 Sensor option.


The Pro Street Tuner software can be downloaded from

You will need the VCI serial number found on the label located on the back of the VCI in order to download. It is important to understand that the device can only be used on one motorcycle.

If you have issues downloading make sure that Pop-ups are not blocked in your browser for the website.

 After installing the software make sure to reboot the PC.

Connect the VCI to the computer and to the motorcycle. The drivers should install automatically once the VCI is detected.

Note you will need separate purchase of Screamin' Eagle Tuner Cable Kit

You should see a green check mark next to the motorcycle in the lower left corner.

On the tuning tab make sure that O2 sensor is selected to wideband in order to get the proper map for ATM.


 Once the file is loaded you can select the program motorcycle button to upload the calibration map.


Run Time Data 01
Run Time Data 01

Run Time Data -02
Run Time Data -02


Spark Advance
Spark Advance

Throttle Position
Throttle Position

Software Versions and Update Information
Software Versions and Update Information

 The ATM cannot be Dyno tuned due to it is always making adjustments to the ECM. If an adjustment was made it would correct the adjustment on the fly. Below is the result of Horsepower and Torque with Stage IV 117 Milwaukee 8, Screamin' Eagle High Flow Exhaust and Ventilator Extreme Air Cleaner.

I found the system to be great! I have over 1500 miles on the bike so far with no issues. I can say that the system is very responsive with one down flaw that is dictated to Harley Davidson by the US government. There is a speed cap of 111.8 mph. If I was a track guy that would bother me, but for the open road I find that plenty fast enough. I have used other software’s in the past and found that Harley did a great job with the package. It is easy, very intuitive and just plain works.






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Reader Comments

Do you know what will happen, if you're using the old orange Screamin' Eagle Pro Street Tuner and modify the AFR? Will the Smart Tune PRO Automatic Tuning Module reset the AFR to their own values?

Hamburg , Germany
Friday, July 21, 2023
Editor Response Good question for a dealer tech. I'll bet if there's any years between the two, you'll be forced to buy an upgrade. Check it out.
Do you offer some free advice or knowledge? I have a 2017 Street Glide special with a 107 M8 built to a S&S 124 bore with a 475c SNS cam. I have the Screamin eagle programmer that I have loaded. A couple of their programs.

Bike is running fairly well just with some hiccups I added the Screamin eagle auto tune and having a lot of running issues now with check engine light. Codes p0031, p0051, and p0134… any help or insight would be great. I do not have any accessory upgrades, except for two brothers exhaust slip ons and SNS big mouth air cleaner. I have a lot of popping and backfiring on mid throttle an heavy throttle. What base calibration should I be using?

The stock 107 calibration or a calibration closer to my setup?

Keith Jackson
Austintown, OH
Monday, July 10, 2023
Editor Response Hey,

You're way ahead of me. I would use the calibration close to your setup. You might need to back down and regroup.
Can I remove the system off my bike by just unhooking it or do I have to reset something, I want to install a power vision, my friend did that and bike runs better.

Sanford, FL
Wednesday, July 6, 2022
Editor Response They all take some resetting. Check the directions.
Seems like Harley took a page from Zippers. I went with the Zippers 'Thunder Max' years ago because they were the only manufacturer with a unit that utilized the closed loop 02 sensors. Been riding trouble free for years now.

Steve Bauman
Mission Viejo, CA - California
Tuesday, February 4, 2020
Editor Response Zipper's is a great group.

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