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Has anyone installed a separate O2 sensor and gauge to see what the air fuel ratio is after making intake or exhaust modifications? The AFR readings at different rpm could show how well the stock ECU is adjusting to those mods and whether an ECU update is necessary.
I installed a wide band o2 sensor on the midpipe and tuned with PowerTronics.
Nearly killed myself: I always looking at the gauge. Be careful if you add a gauge.
I reconfigured map to change every 100 rpm to find and fix a lean flat spot. I also found that with stock muffler (2019), premuffler and cat delete it ran richer in top end, I leaned it out quit a bit on the top. Weird, thought it usually goes lean ? Anyway, runs like a scalded Chihuahua.
Didnt help much with the main problem: lean stuttering and jerking below 4000. For that I added 2 potentiometers and switch across wires coming from stock lamba to make it run at afr 13.5 in open loop, or I switch to other potentiometer circuit for 14.5 for highway cruising. Runs smooth.
Its just too loud now. How do I fix that without putting premuffler back on ?
 

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greetings ! im from philippines, im looking for direct aswer from this forum. ive done cat delete and remove resonator and ive put cheap china yoshimura. the ktm mechanic in my dealer offer me a remap. does it true the stock ecu can be remap or he fooled me as i payed for that thing. and does it harm my engine for decat.? is it neccessary to buy a piggy?
 

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First-Gen Duke 390's can get an Akro-Flash from KTM.
2016 can not.

greetings ! im from philippines, im looking for direct aswer from this forum. ive done cat delete and remove resonator and ive put cheap china yoshimura. the ktm mechanic in my dealer offer me a remap. does it true the stock ecu can be remap or he fooled me as i payed for that thing. and does it harm my engine for decat.? is it neccessary to buy a piggy?
 

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greetings ! im from philippines, im looking for direct aswer from this forum. ive done cat delete and remove resonator and ive put cheap china yoshimura. the ktm mechanic in my dealer offer me a remap. does it true the stock ecu can be remap or he fooled me as i payed for that thing. and does it harm my engine for decat.? is it neccessary to buy a piggy?
You need to add a piggy back to adjust fueling. I think you have been fooled. It wont hurt to remove cat. However the engine does run too lean. Read my post above.
 

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Hi Ross, great to see these experiments and confirmation on the fueling of the second-Gen bikes.
In your post #21 in this thread, I think you confused the open and closed loop.
As for the earlier 390's, although these engines run lean (at certain RPM's) I think they do not run too lean.
No experiences on the second-Gen 390's though.
 
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