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Steve, Motorcycle Mechanic
Category: Motorcycle
Satisfied Customers: 6817
Experience:  30+ yrs. experience, MMI, HD technician, HD early, engine rebuild/performance, bike builder, kit bike program manager, CCI 2001-2004
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2012 harley davidson iron 883. how does my engines computer

Customer Question

2012 harley davidson iron 883. how does my engines computer work? im very familiar with car computer and was just wondering if this harley runs with adaptive strategys and uses fuel trims to compensate for minor faults? i have shortshot vance and hines pipes and was experiencing hesistation and back firing so i put the quiet baffles in figuring it was just a restrictive exhaust i also changed my air filter back to stock. with these changes im wondering if a map is necessary or if the adaptive strategies will notice the difference and act acordingly. the backfiring is almost gone and the hesitation has improved but the problem is still there and also im just hoping for a better understandig of how my computer works
Submitted: 7 months ago.
Category: Motorcycle
Expert:  Steve replied 7 months ago.

your system uses wide band O2 sensors that do correct for minor deviations from stock.

what you need is the STAGE 1 DOWNLOAD.

this will allow the ECM to compensate for most intake and exhaust modifications as well as raise the rev limiter to 7,000 rpm.

you may opt for a tuner instead, but the stage 1 is a good base to build up from and you do not need the expense of a tuner for what you are looking to do.

let me know nif you need more help.


Customer: replied 7 months ago.
what exactly is a stage 1 download? a factory tune i would get from harley?
Expert:  Steve replied 7 months ago.


it is a software program a HD dealership can download into your ECM.

it alters the base algorithms. it increases the fuel percentage, retards the spark and raises the rev limit to make the engine run stronger and cooler. it also allows you to change the air cleaner and/or filter and exhaust.


Customer: replied 6 months ago.
iv heard alot of people on the harley forums saying that stage 1 doesnt do much i was considering the fp3 fuelpack from vance and hines because you can map aftermarket parts and tune based on sensor data. have you had any experience working with these?
Expert:  Steve replied 6 months ago.

I do not, but there are several tuners available and they all do the same thing.

funny you mention Vance and Hines. I never understood how a couple of guys who grew up racing Suzuki's became HD exhaust experts. it's interesting if you think about it.........

I had assumed you came here for professional help.

you could save some money if you would rather read forum posts from people just like you, that know any more about this than you.

let m know if you need more help.

if not, please leave a POSITIVE RATING.

thank you,


Expert:  Steve replied 6 months ago.

let me know if you need more help.

if not, please leave a POSITIVE RATING.

thank you,


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