I have been looking all over the internet to see if this is common problem... with no luck.

Hooked up Power Vision and tried some canned tunes and still excessive decel popping. Looked at DTC codes and consistently getting rear 02 sensor open/not responding. So I set up the gauges for each 02 sensor and sure enough the rear one stays at 5 volts while the other one starts dropping as it warms up. So I swapped the sensors thinking one is bad (both same length...) Rear one was black and the other was grey. After swap same problem rear 02 sensor open. So its not the sensor. Same thing on stock tune...

So I tried to trace the wires back to the ECU, yeah good luck. They take off into the frame under the swing arm bushing and I cant find the same color wires popping out anywhere. So I pulled the ECU connections and they all look good. Sensor sleeves read as grounded on the DMM.

IS there a way to test the connection back to the ECM or some other place?

What happens if I switch closed loop =0? And run it open loop. Can I just run it like that until I figure the sensor out.

Here are the mods I have done myself

Rough crafts pipes (Short shotgun pipes see attached photo), 4" K&N, Wire tuck.

I noticed the bung on the rear pipe is kinda long like 2-1/2-3 inches so the sensor isn't really in the path of the exhaust but it should still read something.

Sorry for the long post just trying to eliminate all the things I have done already...

Thanks

 

There is a complete set of schematic wiring diagrams in the back of the Service Manual that will tell you where those wires go.

If you don't have the SM, get one. It's just as important as the rest of your tools.

 

I have a manual on order. But I found a wiring diagram online. Pin 23 on the ECM connector is the one I was looking for, I have continuity to there from the sensor connector. and the ground wire to ground so it's not a faulty wire issue.

It was total pain in the *** pull the ECM (I thought I had done it yesterday bu that was the security unit) on a 2011 model but as it turns out it was a good thing because I did another wire tuck and got rid of that hunk of plastic behind the rear jug and moved the ECM under my Rough Crafts seat which fits nice and has lots of air flow while still out of the rain. I will start a new topic showing my results... looks way better.

But now I have no idea what could be wrong with my sensor. I know if I take it to Harley they will laugh at me with all mods I have done... I already got my extended warranty money back because my bike will likely be void of any warranty. So it's me my multimeter and this forum.

-So I will head over to the Power Vision forum and see how/if I can run it without sensors for now.

-I think over the weekend I will try to put the stock headers back on and see if that works. I am still a little suspicious that the bung on the rear Rough Crafts pipe is too long and it is not letting the sensor do it's job.

-I might first run some extensions and cross the sensors to see if I get the front reading the back and back the front. I have heard of people doing that by accident and it doesn't blow anything up.