I installed a Ness big sucker, V&H Monster Ovals and a Cobra Fi 2000 auto tuner two weeks ago. Bike ran fine. Never checked codes. Yesterday I installed V&H Power Duals. Bike runs awesome. Just for chits and grins I checked for codes and its throwing P0134 and P0154, front and rear O2 sensors inactive.
Where should I be looking? The stock sensors are hooked up correctly, so I'm leaning towards the tuner. When I changed out the headpipes, the sensors looked pretty black, but I have no idea how to read O2 sensors.
I spoke with Cobra about the tuner causing the issue, but they dont think that its the case. They ARE sending me another circuit board to see if that is the issue.They suggested that maybe the stock sensors arent long enough to be in the stream to be getting a reading. Does this sound plausable? Thanks,I'm stumped.
Oh yeah, its a 2010 limited.

 

Your O2 sensor bungs are probably to long and not letting the sensor protrude into the pipe, simple fix is to have an exhaust shop cut the bung out, cut it down to where the sensor will be in the pipe and re-weld the bung into the pipe. I have seen this on many after market exhaust systems on cars also, we use a simple fix as stated above. Also couldn't hurt to use a propane torch to burn the carbon off the sensor's before re-installing them, DO NOT use solvents to try and clean them, HEAT only or replace the sensor's.

 

Doesn't anyone make a longer sensor? I thought I had read where there was a auto one that was like an inch longer, but now can't find the info. There has to be an easier fix than removing it all and cutting into it. Heck,if I had known this , I woulda just gutted my stock pipes.

 

Well the Auto Tune sensor may be longer, but they are a 5 wire sensor, your sensor's are 2 wire, so they will not work. I saw that you have a 2010 Ultra Limited are you running the factory 12mm (small) sensors, or the 2009 and earlier 18mm (large) sensors? If you are running the 2009 18mm sensors your ECM will not read them unless it has been reflashed by the dealer.

 

Slightly off topic, how did you check codes?

 

I still have the stock sensors in it.

 

Really? I ran the diag on the odometer. As far as reading the service manual, been looking and cant find anything thats helping.

 

No, I meant, how do you check for error codes? Never had a FI Harley before.