Alright, I set the tune back to DAG 205-04 and changed the CI to 110" in the tuning constants. Bike runs GREAT, plenty of power at all throttle positions. I attempted to Vtune and started seeing the 'valley' begin to form. I stopped attempting to tune. I recorded 'generic O2' and watched the sensor readings. They start at 5000mv and come down to about 800 and fluctuated down to 80mv. I don't have any prior recordings to compare to but I don't think that looks right. Is there a possiblity that the sensors are contaminated? I over filled the oil tank and drove about 15 miles on the highway before I realized it. I pulled the breather out of the AC and made a mess on my engine. I contacted S&S and they said" Our testing has shown that the placement is optimal for proper operation of the sensor" Tom Hampton, Technical Support S&S Cycles. I like the way the bike runs, but I do need to get it on the dyno.
Do tuners use there own sensors or do they take the readings from the bike?

 

They all say that, but most of the time it is incorrect. I gave you the way to tell for yourself and if you search for the Bosch specifications they will tell you what I did in more technical terms. I would run it and see if things change over time. If they do that will tell you the ECM is getting bad readings from the O2 sensors. I doubt that the oil tank caused them to go bad but anything is possible.

 

I am not doubting what you said Steve, I'm just looking at options. I looked at Bosch O2 specs and didn't see any depth spec. If I look down the pipe, I should see most of the sensing element, right? Before I remove my exhaust, I'm going to try my old sensors and do a Vtune run to see the results. If I'm digging that valley again I'll have to cut down the bungs. That will have to be after Laconia. Like I said the bike is running good.

 

If you have the Bosch specifications they give you how to make the mounting bung. There is a complete drawing of how it is to be made. If you take that and install a sensor to it, you will find the result is how I described it to you, end of the threads flush with ID of pipe. There are also specifications for the max allowable angle off the center line of the pipe too. I wish these aftermarket exhaust guys would really fix there problems but they haven't yet and they have all been told how and why they need to for over 10 years.

 

Steve Cole, what is your experience with bung depth on the Softail Fat Cat. I have a perfect tune but perhaps the afv should be zeroed on occasuon?
Forgive the hijack Mike

 

If you go out for a ride and then come back and reset the AFV values. Then go again and feel differences, then somethings not right. People need to understand the ECM just uses the O2 reading to correct the mixture as you ride. IF the O2's are not working correctly or are installed improperly giving false reading the ECM doesn't know any better and will adjust away. The same is true if the O2's are Wide Band or Narrow Band sensors, all the engine modification play apart in what one can get away with. Just as HD has done a poor job of mounting the sensors in the pipes but gets away with it due to the CAT and restrictive mufflers. Remove those and the Stock pipes screw up the O2 sensor readings. So there is no one size fits all way that you can use them, only a good rule of thumb to follow when you start then you must test what you've done. This is why so many people blame O2's for being bad and not necessary, but they are very good and work very well when installed correctly.

 

Well as I thought you are correct Steve, thank you. I put my used sensors back in and got the same results. I plan on milling down the bungs to get better depth this winter. In the mean time I will call DrDyno and ask if he can tune it like this. I have put the newer sensors back in and am riding it with the DAG-205-04 cal set to 110ci with the IVO set to 2 (because that is what camtune came up with) IVC is at 2. The bike runs strong. but as the ride goes on I feel a drop-off in power and some "burping" thru the intake. Could this be AFV affecting my tune. When I reload the cal, it runs good again. Thanks again for all your help.

 

Well, through the long winter I took my exhaust off. Cut off the old angled bungs, bought straight bungs from Bung King and had them welded on. My O2 sensors are now almost completely in the exhaust stream. I just started Vtuning, and will keep you updated.

 

I have had good luck with screwing around with sensor depth and sensor responsiveness. One thing I have notice. From a dead cold start. Unheated sensors come on line much quicker after my mods.