PCIII/O2 Sensor

[JimLor]

I’m always looking for a new farkle to improve ole Maxine. I’ve read some of the recent “praise” threads for the PCIII and am very interested. I would appreciate it if someone could/would take the time to ‘splain what the PCIII actually does, what the O2 sensor does, what happens when you disconnect the O2 sensor, does one have to do the Barbarian mod (w/CO changes) in conjunction with the PCIII install, what “map” comes with the PCIII (and if as reported in the latest thread, it’s “bone stock,” then how does it improve performance?), are there adjustments you can make on the unit itself (not new maps) and finally, how do you make a woman happy!? :dribble:

Thanks.

Jim

 

[ionbeam]

First approximation, others will be along to refine, add, change and correct.

The Power Commander's (PC) primary job in the FJR is to alter fuel injection mapping based on % throttle opening and RPM. The PC adjusts the fuel injection pulse +/- some % from the stock ECU map. It has an optional 'accelerator pump' feature that enriches FI upon pinning the throttle. There are many basic FI maps available for the PC. The real power of the PC is when you put Exhaust Gas Analyzer (EGA) bungs in each head pipe then run your FJR on a chassis dynamometer and have it create a custom map that matches your engine exactly.

The various maps add or subtract fuel to compensate for the stock ECU map that is pretty much dedicated to emissions first. Some maps alter the ECU map to enhance throttle smoothness. Some maps can be set to optimize either economy or power. If you make changes to your FJR such as pipes and intake filters the PC will let you match the FI to the new engine flow rates. Someone will be along with a link to Wally's Smoothness map, I'm sure!

The O2 sensor measures the amount of oxygen in the exhaust. The O2 sensor only works once warmed up. It supplies the ECU with a voltage that is proportional to the amount of oxygen so that the ECU can adjust FI to meet some value that equals optimum emissions. In the FJR, the O2 sensor is only read by the ECU when the engine is fully warmed up and running at a basically steady rate. The O2 sensor gets disconnected to prevent the ECU from compensating for FI mapping changes made by the PC.

The Barbarian Jumper (BJ) makes a minor adjustment to the FI system, the adjustment result is most predominant at or near idle. The BJ offset to the basic FI map is a one dimensional adjustment. The PC is more of a '3D' adjustment because it takes in consideration all RPMs, throttle position and rate of throttle changes. It would probably be best to return and BJ adjustments back to stock before installing a PC but in the end, it may not matter much.

The PC software lets you read all the maps, and should you be an intrepid twiddler, it will let you change anything and everything. There are also quick adjust buttons on the PC itself.

how do you make a woman happy

That should be another thread. Probably never ending and never resolved.

 

[SkooterG]

Jim, all the answers to your questions are out there and have previously been covered in depth. Several times. Try the search - you should get a plethora of threads with valuable information.

 

[Pierre]

First approximation, others will be along to refine, add, change and correct.
The Power Commander's (PC) primary job in the FJR is to alter fuel injection mapping based on % throttle opening and RPM. The PC adjusts the fuel injection pulse +/- some % from the stock ECU map. It has an optional 'accelerator pump' feature that enriches FI upon pinning the throttle. There are many basic FI maps available for the PC. The real power of the PC is when you put Exhaust Gas Analyzer (EGA) bungs in each head pipe then run your FJR on a chassis dynamometer and have it create a custom map that matches your engine exactly.

The various maps add or subtract fuel to compensate for the stock ECU map that is pretty much dedicated to emissions first. Some maps alter the ECU map to enhance throttle smoothness. Some maps can be set to optimize either economy or power. If you make changes to your FJR such as pipes and intake filters the PC will let you match the FI to the new engine flow rates. Someone will be along with a link to Wally's Smoothness map, I'm sure!

The O2 sensor measures the amount of oxygen in the exhaust. The O2 sensor only works once warmed up. It supplies the ECU with a voltage that is proportional to the amount of oxygen so that the ECU can adjust FI to meet some value that equals optimum emissions. In the FJR, the O2 sensor is only read by the ECU when the engine is fully warmed up and running at a basically steady rate. The O2 sensor gets disconnected to prevent the ECU from compensating for FI mapping changes made by the PC.

The Barbarian Jumper (BJ) makes a minor adjustment to the FI system, the adjustment result is most predominant at or near idle. The BJ offset to the basic FI map is a one dimensional adjustment. The PC is more of a '3D' adjustment because it takes in consideration all RPMs, throttle position and rate of throttle changes. It would probably be best to return and BJ adjustments back to stock before installing a PC but in the end, it may not matter much.

The PC software lets you read all the maps, and should you be an intrepid twiddler, it will let you change anything and everything. There are also quick adjust buttons on the PC itself.

how do you make a woman happy

That should be another thread. Probably never ending and never resolved.

Thanks for the explanation.

I have the PCIII + Devil Exhaust can on the bike, should I change the air filter for a K & H ?

 

[SkooterG]

Thanks for the explanation.
I have the PCIII + Devil Exhaust can on the bike, should I change the air filter for a K & H ?

I assume you mean K&N?

I wouldn't. It doesn't offer any performance advantage. The one advantage is that it is re-useable. But for me, cleaning it is a PITA, so I don't even use mine any more. I have gone back to using OEM Yammie air filters.

 

[Pierre]

Thanks for the explanation.
I have the PCIII + Devil Exhaust can on the bike, should I change the air filter for a K & H ?

I assume you mean K&N?

I wouldn't. It doesn't offer any performance advantage. The one advantage is that it is re-useable. But for me, cleaning it is a PITA, so I don't even use mine any more. I have gone back to using OEM Yammie air filters.

Thanks, just saved $ 100.00 !!!

 

[JimLor]

ionbeam - thanks for taking the time to explain! So, let me riddle this - if the O2 sensor only reads and adjusts when warm - to meet emissions - if one were to disconnect the O2 as a distinct and separate action (no PCIII connected, no Barbarion mod, etc) would that result in a richer mixture across the board? Any adverse effects? I saw a recommendation to do just this on the board and was wondering...

Thanks again.

Jim

 

[SkooterG]

if the O2 sensor only reads and adjusts when warm - to meet emissions - if one were to disconnect the O2 as a distinct and separate action (no PCIII connected, no Barbarion mod, etc) would that result in a richer mixture across the board?

From the un-exact info we have it should, but only so much. When O2 sensor is in operation, fuel injection is in "closed loop" mode. When the ECU is not using the O2 sensor, it is in "open loop" mode and using only a "base map" to determine how much fuel to inject. Besides during warm-up, acceration, and any other modes, if your O2 sensor were to fail, the FJR keeps running using only the base map. Not *ideal* considering the closed-loop design, but works just fine.

Any adverse effects? I saw a recommendation to do just this on the board and was wondering...

Shouldn't be any adverse affects, as FJR was designed to run this way in case of an O2 sensor failure. I don't think I would go so far as to recommend it, but try it and see what happens. You might see a small reduction in fuel mileage though.

What the PCIII does is "piggyback" onto the "base map" stored in the ECU. It generally adds more fuel from what the base map is calling for. Especially in partial throttle applications, where it really shines and greatly improves the *throttle response*, or as some would call it - herky-jerky throttle. The PCIII adds infinite tunability to the fuel injection, instead of living with only one "base map" that is stored in the ECU.

 

[JimLor]

Thanks ScooterG - Nice to read some "man" talk. I just left the color coordinated helmet discussion - it was awful, I knew I shouldn't be reading it but I couldn't help myself! :dribble:

 

[ionbeam]

if one were to disconnect the O2....Any adverse effects?

Yes!!! Greenpeace would put you on their hit list and all the environmental activists would hunt you down like a dog Other than that, you should notice no difference in operation and no change in gas mileage.

 

[SkooterG]

Other than that, you should notice no difference in operation and no change in gas mileage.

Ok, I'll bite. If running in closed loop mode with the O2 sensor leans out the fuel mixture, than why wouldn't stopping that mode result in a small increase in fuel consumption?

 

[ionbeam]

Ok, I'll bite. If running in closed loop mode with the O2 sensor leans out the fuel mixture, than why wouldn't stopping that mode result in a small increase in fuel consumption?

Technically, gas mileage will go up. Practically, I don't believe you would be able to measure the difference. I've had my O2 sensor in & out of service several times for several tanks of gas each, (without my PCIII connected) and with my style of riding, over the roads I typically travel, I saw no difference in mileage. This was done primarily during my commute which sees a pretty steady 50 mph for 1 hr each way. Since I saw no difference nobody else should either :lol: Perhaps if someone did a full tank at a steady speed, first with the O2 then the same route again w/o the O2 they may see a difference.
I'm pretty sure Yamaha was more concerned with making 2009 emissions ratings than mpg ratings.

Facts or solid information anyone?

 

[fossilrider]

Ionbeam, when you disconnected the O2 sensor (without a pcIII), did the check engine light come on? Any error code?

Thanks Fossil

 

[ionbeam]

did the check engine light come on? Any error code?

Surprisingly, no. No light, no code. It seems like the O2 light comes on when the sensor is out of expected range, but doesn't come on when open circuit. I'm sure the system was designed that way, thank you Yamaha.

Earlier models of FJRs used to have the O2 light come on when bike got really wet while washing it :blink: It used to be a common complaint, but I haven't read any grumbling about it in a while so maybe Yamaha has done something to fix it.