The O2 sensors on my SG are just inches after the pipe comes out of the cylinder. Even on the 10's I believe the Cat is in the common pipe where the 2 come together, so the sensors should be before the cats. (Touring bikes that is)

 

On the Dynas the sensor is upstream of the cat, on the header pipe. No trouble lights came on after their removal and replacement with non-cat performance mufflers. My understanding (which is quite limited) of the O2 sensor's function (on a Harley anyway), is to provide a signal to the bike's fuel management system so it can control fuel to air mixture. The fuel enrichment devices (such as the XiED) simply alter the signal from the O2 sensor so that the fuel management system adjusts the ratio a bit richer (which results in a cooler running engine).

 

those things do not belong on a HD

 

But it's coming, we usually keep current on ECM trouble codes and changes! They Harley won't set a code now but probably will in the future when you tinker with the cat, if but a hidden code that will let the dealer know if the cat has been tinkered with!

EPA's gonna get ya!

 

Crusty, you are incorrect sir. I have pulled exhaust systems on every model except V-rods, 06 - 08, and the mufflrer to the front cylinder has had a cat. It is even stamped on the back side of the muffler "CATYLIST". Have not looked at 2010s, so it may have cats in both mufflers. The 2010 tourers have the cat in the head pipe.

semper fi

check 6

Bwana

 

Well, bwana, I've been wrong before. All I know is that both of the mufflers (from my 2010 FXD) sitting on my workbench have cats (and markings that say 'USA CATALYST'), and neither of the headers have cats. The local dealer mechanic tells me that the Dynas didn't start having cats anywhere in the exhaust system until 2008, and that they've never seen a bike with a cat in only the front cyclinder exhaust system. I know the touring models all have cats in the headers and not the mufflers.

Were you working on California models? I'm not in California.

Semper Fi,
krusty

 

Crusty

All bikes were in the southeast; FL, MS, TN, AL. Don't believe everything the dealer mech tells you, cause I can guarandamntee you that the 06, 07, and 08s had one cat in the front cyl muffler and the CA bikes were this way starting in I believe 2004. If your 2010 Dyna has CATS in both mufflers, than I assume that all 2010s have the two cats and that the tourers have a CAT in both headpipes.

Bwana

 

I just checked my 09 dyna pipes....no cats, no stamp.

 

Cali & CVO have had em for a while, lower state odd years in one muffler different models!

None on state 09 bikes, they had a narrow band heated 02 sensor in the exhaust stream from each piston, EPA CAM and Lean AFR to help meet the requirements without the use of a CAT.

2010 the Emissions Standards got real strict, all of the above plus the addition of catalytic converters in the headpipe all the baggers and in the mufflers for every other model.

All the 2010 Metrics have the cats also! I had a thread that caused a lot of controversy "Build a Better Mouse Trap" alluding to the fact the industry needed to join forces and find some other way than a Catalytic Converter to meet the new 2010 EPA emissions standard's. I said I would revist the thread after the summer of 2010 when all the big heavies went through the hot months of July and August!

More and more threads about the Cats and no need to get into a tizzy just yet! I don't believe a Cat belongs an Air Cooled engine! They may as some of the metrics water cooled work on certain typed of water cooled engines but not the Harley!

A 100 year old design that depends on its signature sound, "a free flowing exhaust" as one of it's main selling points! Might be able to water cool the heads but the bottom end is where the sound comes from! Harley in particular needs to do some R&D towards coming up with another way of meeting the emissions standards.

We all are aware of the Harley Tax, we change that exhaust out anyway and make other mods, hardly anyone is satisfied with a harley right out of the box. Most of the stuff we do for performance will help cool one down and make it sound more like a Harley!

Just saying, it ain't just Cali and CVO bikes anymore, it is every 2010 model and beyond. You can't skin em all without drawing the evil eye of the EPA. We lose our aftermarket people and we are screwed!

 

you have either 1,2, or 4 o2 sensors.
If you have one, it is before the cat always.
If you have a twin cyl with 2 sensors they are always before the cat.
If you have 4 o2s, two are before cat for fuel mixture metering, two are after for catalyst monitors.....thats what I was getting at.

ALL OBD 2 and later systems are 4 sensor systems. I dont know what Harley is using because I never looked. But I bet they are a step behind cars and trucks and only using 2 sensors for fuel metering only.


The day they use 4 will be the near death of Harley because then the only way you can lose the cat is to use an o2 eliminators, or reprogram the computer to not look at the secondary o2 sensors. So if the cats are in the mufflers, you would be stuck with stock mufflers with cats, or aftermarket pipes with cats....the old harley sound will be lost unless you are a tech geek and can reprogram the computer, or fool the sensor readings.