Hello all,
I own a 2016 Iron 883 and it's almost completely stock, I decided to put some 60$ slip ons on from amazon, and after installing it and taking it for a ride it felt super sluggish. There were no codes or lights initially on the ride or after. I proceeded to return the slip ons and reinstall the stock exhaust. Now its the next season, approximately 7 months since I last started or rode on it. Went to start it and half of the odometer lit up and the rest flickered. Dead battery I thought so I hooked up jumpers and tried jumping it, it would start but idle very poorly and had a reed light on in the middle and the check engine light. Went ahead and entered diagnostic mode and got the codes P0131, p0151, p0506, and U0156 finishing with pn00125-01 which I've read is just the serial number of the ECU. Any ideas? The codes apparently mean incorrect A/F ratio, 02 sensor bank 2 sensor 1, IAC system rpm low, and I couldn't find what the U0156 means.

 

This code means that the Information Center "A" (IC-A) and other control modules on the vehicle are not communicating with each other. The circuit most often used to communicate with is known as Controller Area Network bus communications, or simply put, CAN bus.

 

Any idea what these codes mean? Could it be bad gas or just the battery not being charged fully?

 

Could it just be that my battery is so dead all of the systems are going haywire? I should have left on a trickle charger over the winter but it's my first bike and didn't know. What worries me is the code for the A/F and the sensor code. And apparently U0156 is lost comm with speedometer.

 

Start by eliminating the battery as a problem, which you already suspect. Charge it up fully and get it load tested.
Clear the codes and see if any come back.
You need a battery tender for winter storage, not a trickle charger. Also, fuel stabilizer in the tank when you park it for the winter.

 

i ride gravity, it never fails!
i would have to see what my library has. if the controller is dead, then nothing will work right. at one time, the speedo had all of this but things changed over time. you might want to consult the xlforum and the sportsterpedia.
easy to have the battery load tested.
kiss it as they say. check terminations. i recently had a no start and it was the connector in the headlight bucket.

 

Considering you just messed with the exhaust, codes P0131, p0151 are probably from an exhaust leak or loose 02 sensors and/or connections ( there are other causes, but check those). Did you use new gaskets, etc.?

P0506 Idle Speed Control RPM Too Low, could be related to the other codes as well.

Start with getting the battery load tested.

 

About to take the battery up to harley to get it charged and load tested, what do you mean by new gaskets? The slip ons were just slip ons, not a full exhaust system, it was just held with an exhaust pipe clip. I did go to HD service department and the lady there recommended I should pump the oil I put in it out since after the bike sits apparently the oil pools in the engine and you don't get an accurate oil level reading without starting the bike first. I'm starting to think I overfilled the oil heavily and that caused the poor running. I'm going to eliminate the oil and battery first by doing an oil change as well and putting the correct amount in on refill. Thank you all for the helpful tips so far, I'm going to keep going down this repair path and update y'all!!

 

Soooo bad but possibly good news: battery is all charged and the bike starts up. I also changed the oil after draining what I could with a pump. The issue comes with the oil that I changed. It didn't seem right, I have attached photos of it, seemed like it was either milky or metallic. Literally bought the bike at 2200 miles and put 400 on and rode for not even a full summer. Let me know what you think. Also the codes did not come back after they cleared but I still have an oil light on and the engine does not sound right.

 

That's water in the oil. A lot. It happens when the bike is started up and not ridden long enough to burn off the condensation. Some owners feel that they have to start up the bike every once in a while during storage in the belief that the bike shouldn't sit for long periods or they just want to hear it run.
It's too bad you didn't change the oil when you first bought it, but hopefully you didn't do a lot of damage.
Hard to know what you mean that it doesn't sound right, a better description or a good video might help.