Advice wanted

[Franco58]

Ok, here I go again.

I've got an 08 S4Rs with the stock ECU, full Arrows, open airbox and a PC III.

Dynojet says that I shouldn't run the Lambda sensor with the present set-up. My buddy said that my bike's spewing raw gas (i.e.; very rich) when running through town. Does anyone know if disconnecting the Lambda sensor with improve things, make it worse, or cause no change?

TIA,
Frank

[devimau]

If you disconnect the lambda sensor the system will  pop the engine light on, switch into the backup mode (1 sensor is not working..) and run poorly (even worst than now).
I suggest you to send your ecu and have it reflashed, the pc3 won't modify values below 5k and therefore the bikes run poorly @ low rpm's.
With the flashed ecu you will be able to trim each cyl to smooth out the ride and find the perfect air/fuel mix @ small throttle and with the pc3 you can custom map it and make it perfect @ wot and higher rpm's.
That would be the most inexpensive way to do it, then you can buy an aftermarket fully programmable ecu and spend from a grand and up.

[Bill in OKC]

There were several threads about PC IIIs not working right with the stock ecu and o2 sensor connected.  With the arrows and open air box you need to get a DP ecu (or flash your stock ecu to DP specs) and ditch the o2.

[lofty55]

You should have reflashed your ECU rather than getting pc3 IMO. I have an s2r. I have full arrows with beast-r intake and dp spec ECU. NO power commander. Had my bike tuned by my guy. Check it,

Arrows full carbon system - 1200
Beast-r - 350
Crankcase breather - 25
ECU reflash - 470
Pro tuned with vdst - 200

Total $2245

Runs like a dream. And this was the cheap route! Couldn't afford the termis.

Hope you figure it out. When you get it right, you will love the way it revs/responds. Well worth it. The guys are right about disconnecting the sensor with stock ECU. Not a good idea.