Why do you have to remove or disconnect the O2 sensors when you install a PC V? I know the pipes I put on have the CAT removed but is there a benifit to having the sensors?

 

My understanding is that the PCV does that job that the 02 Sensors are there for, so they are no longer needed. That's why the PCV comes with the the 02 eliminators and you need plugs to fill the 02 Sensor ports in your pipes.

 

The PCV operation depends on known/predictable ECU behavior as it works as a delta off of it. Thats one reason you must know what map you are running in the bike along with its state of modification to select the right PCV version. The ECU adjust its behavior based on the O2 sensors, which makes it unpredictable and that makes a mess of the PCV. The PCV is a completely open loop system where it simply makes the best guess based on what works well for most riders, and the O2 sensors must be disabled so they do not interfere with what the PCV wants to do. You can also have a PCV equipped bike professionally tuned.

The benefit for O2 sensors is that the characteristics of gas you buy today that affect AFR changes from tank to tank, and the only way to adjust for that is via the O2 sensor input as well as the ION knock sensors. Since the PCV has no O2 indirect AFR feedback, it has to run very rich to be sure your bike doesn't melt when you happen to load up on the wrong blend. Using the O2 sensor allows you to tune closer to the edge (but not too close) and not worry so much about the fuel, or in other words, to be able to get the most out of the fuel you have (power, mpg).

In practice, PCV bikes run well enough, lots of happy customers. But if fuel gets crappier and crappier I dunno.

The much more expensive and optional PCV auto tune modules add broadband O2 sensors back into the mix in an attempt to compensate for fuels as well as other engine modifications. There are several aftermarket products and methods to accomplish this, some better some not so good depending on your situation and skill.

 

ca I connect to my PCV and download the map which is on my bike now? It was pre loaded by Fuel Moto I am assuming I can use the software and get the map from it while on the bike.

 

Yes, you can connect to the PCV and dl the map while the unit is on the bike.

(The AT module is not much more expensive - it is about the cost of a PCV.)

 

Everything is relative, the PCV new is a few hundred $$ to begin with and when you add the few hundred $$ for the autotune modules, it makes an expensive several hundred $$ tuning system and expensive for what you get in return. Don't want to turn this into another "whats better" thread but just saying, for the new guys here, that most riders (late model bikes) often can do better for much less cash and effort.

 

The PC5 can be used either open loop or closed loop.

The open loop bypasses the O2 sensors and runs off the fixed map installed in the PC5.

You can purchase the O2 closed loop sensors and add to the PC5 and use wide band sensors in the O2 bungs and get automatic fuel trim to enhance the installed map.

Install the PC5 software on your computer.

Hook up your computer to the PC5 and click on "get map".

Then save that map with a name that will help identify it if you wish to modify or reinstall it.

To install a map, load the map into the software, then click "send map".

 

Maybe I'm misreading your post but........
The PC doesn't guess at anything. It modifies the signal coming from the ECM via a map installed in the PC. Also, it isn't necessary to run rich values in the PC. If fuel gets worse it's easy to change maps.

 

I'd rather my bike ran rich then lean.

That doesn't sound very practical especially when riding several hundred miles in one day. I think I'll stick with my O2 sensors and let them do their job.

 

Of course it wouldn't be practical to continually change maps. I haven't found it to be necessary on my cross country trips.