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Discussion Starter #1
New 2019 Street Bob, about 3 months old. At 1500 miles had some upgrades done: Vance&Hines big radius, Harley heavy breather, Harley pro street tuner, and stage 2 torque kit. All the work was done by the dealer. They used a map for stage 2, though it's probably not tuned right for the short pipes...

Sounds great when you fire it up, engine idles OK, runs smooth. I can ride for ~20 miles before I get a check engine light (seems to pop up in 2nd-3rd gear, noticed it once while engine braking). While light is on the performance drops and it starts backfiring on decel. Codes come back O2 sensors, front and back. I can reset them, then this repeats -- rides smooth for a while then O2 sensor codes.

So I'm pretty sure it's a bad tune / too lean, but I'd love to hear opinions. My big question is what to do... this is the first bike I've bought new and I'd like to keep it in warranty! Right now they are recommending a dyno (and the tune would sure be nice), but I'm concerned there won't be enough headroom with the Harley tuner to deal with the O2 sensor issue. Plus it would be out of pocket. Should I give it a shot or suck it up and go back to stock pipes on their dime?

Advice appreciated!
 

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Sounds like you already know the answers as defined by your desire to keep it within warranty. Its possible a a dyno tune on the pro street tuner will help solve your problem, or at least help you decide whether you can run those pipes or not under those limitations. If not and you have to go back to stock exhaust, you will probably need another dyno tune or to run the canned map so its an expensive attempt. They should experiment at their own cost to see if the stuff they sold you will work together, not yours.
 

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Yeah at the end of the day it just seems a shame to waste the warranty, a few years down the road will be another story. Thanks for the advice, I'll make it clear that if it doesn't work out then redoing exhaust and dyno is gonna be at their cost. Somehow I see that not going over well haha... I'll post back, thanks again
 

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Thanks for the advice everyone, it's being run today. Hopefully they can sort it!
I hope you post back with details. It would be good to know how it works out & if the moco tuner will allow enough AFR change to accommodate the cam & exhaust change combo. I'm kinda curious as to whether it will even handle just the cam change with stock exhaust if you end up having to back to that.
 

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Discussion Starter #8
Update: They ran the dyno and bike was running great, smooth throttle through all gears. Did ~160 miles this weekend, no issues. Monday morning though, check engine popped back on. I'm not sure if it's an O2 code but I assume so, the trigger was the same (slowing down to 20-30 through a toll station, engine breaking in 2nd-3rd gear). Bringing it back in on Thursday, I can't really think of anything else to try but going back to stock exhaust. For now I'll keep the stage 2 and intake, I do prefer it over stock (looks and knee clearance).

 

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With your set up there’s no reason why they can’t get it to run right with a good dyno tune.


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Are you thinking they just don't know what they're doing? I'm not very familiar with the Harley tuner, but my understanding is that the software doesn't give you much flexibility in AFRs due to emissions restrictions. Like I'm not sure whether you can just dial down low/mid-rpm enleanment? I should just buy the damn cable and see for myself, they really should include the cable with the tuner.
 

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Are you thinking they just don't know what they're doing? I'm not very familiar with the Harley tuner, but my understanding is that the software doesn't give you much flexibility in AFRs due to emissions restrictions. Like I'm not sure whether you can just dial down low/mid-rpm enleanment? I should just buy the damn cable and see for myself, they really should include the cable with the tuner.


They either lack experience or are using a canned tune and then running it on a dyno to see the results.


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Are you thinking they just don't know what they're doing? I'm not very familiar with the Harley tuner, but my understanding is that the software doesn't give you much flexibility in AFRs due to emissions restrictions. Like I'm not sure whether you can just dial down low/mid-rpm enleanment? I should just buy the damn cable and see for myself, they really should include the cable with the tuner.
New 2019 Street Bob, about 3 months old. At 1500 miles had some upgrades done: Vance&Hines big radius, Harley heavy breather, Harley pro street tuner, and stage 2 torque kit. All the work was done by the dealer. They used a map for stage 2, though it's probably not tuned right for the short pipes...
I'm confused. Your own post says they used a "stage 2 map". If they put the pipes on and tuned it then why would it not be tuned right for the short pipes? Did they tune it or did they load a canned map?
 

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I'm confused. Your own post says they used a "stage 2 map". If they put the pipes on and tuned it then why would it not be tuned right for the short pipes? Did they tune it or did they load a canned map?
My impression is that they originally loaded a canned map for the the cam change and then tweaked that map on the dyno runs to try to accommodate the exhaust change.

What I think will be interesting is whether going back to stock exhaust will cure the problem or not. Ideally another dyno tune will be done for that.
 

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Discussion Starter #14
Initial install was a canned map that should have been appropriate for the upgrades (stage 2 + exhaust). Issues since (see above), and in their words the canned map may not necessarily appropriate for non-Harley parts (pipes). So the suggested next step was to tune (dyno).
 

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Should’ve been tuned on the dyno first not just the canned map.


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I'm not an expert but I disagree. The canned map for the cams was probably the best baseline map to work from as the bike probably would have run like crap on the stock map after the cam change, if it would even run.
 

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I'm not an expert but I disagree. The canned map for the cams was probably the best baseline map to work from as the bike probably would have run like crap on the stock map after the cam change, if it would even run.


Should have been run on dyno before the work and then after. That’s how my bike was done and it ran excellent. No canned map was used.


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Should have been run on dyno before the work and then after. That’s how my bike was done and it ran excellent. No canned map was used.
Sure you can dyno before if you want to see the performance delta -- at your cost. Otherwise I don't see how that's relevant? Canned maps should be fine with harley parts, they are tailored to the bike and upgrade(s). Though obviously there will be room for improvement with a proper tune.

That argument aside, it's been run on the dyno now post-upgrade, and the tune is still not working out. To your earlier point, "maybe they are just using a canned map and then running it on a dyno to see the results"... man I would be pissed... I really have no way to verify what they did, other than their word. Suppose I could bring it to another shop.
 

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My bike was run on the dyno prior to upgrades. Dyno tuned after upgrading. Then I ran it 1000 miles and brought it back and one last dyno done. All included in the pricing/ work which I was given an accurate estimate prior to work being done. I got printouts of all the dyno runs also.


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My bike was run on the dyno prior to upgrades. Dyno tuned after upgrading. Then I ran it 1000 miles and brought it back and one last dyno done. All included in the pricing/ work which I was given an accurate estimate prior to work being done. I got printouts of all the dyno runs also.
Nice! I like that approach and obviously you get what you pay for. Your printouts -- details, or just power/torque vs RPM curves?

Assuming that my shop is competent, the "after" tune should be fine (and "before" run irrelevant). My suspicion is that they are running into a wall in terms of what the Harley tuner can deliver, and don't want to admit it...
 
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