If the fuel injectors were gummed up and not operational, then the fuel pressure regulator is suspect, as well. Pressure too high. If your version of regulator is the one with the vacuum line to it, they degrade and need replaced. Same for the MAP sensor and its associated vacuum lines. Continue with fuel system cleaning such as Seafoam or Techron or B-12.
The 2011 RS has a single O2 sensor, located downstream of the Y-pipe, in between the Y-pipe and the inlet to the muffler. It is tested with BUDS. More on that later.
Yes, an exhaust system leak from a leaking gasket can cause a mixture problem with the O2 sensor operation and engine mixture. Much has been written about the subject. Upstream of the O2 sensor, air is drawn into the exhaust line from the leak. That happens because in between piston power/pressure pulses, the pressure inside the pipe drops. This, combined with the Venturi effect of the gases flowing past the leak, causes air to be drawn into the pipe.
If the leak is upstream of the O2 sensor, the sensor “sees” an increase in O2 level, which indicates a lean condition. Remember that the ACTUAL combustion condition hasn’t changed. Thus it’s a false lean condition due to the air leak. The O2 sensor output voltage goes down, the ECU sees the voltage drop, and increases fuel delivery to try to raise O2 sensor voltage back to normal. The actual operating condition of the engine becomes rich, even though the ECU believes there is a lean condition.
If the air leak is minor enough, the increase in fuel flow and rich condition of the engine, can rebalance the O2 concentration in the exhaust pipe. The O2 sensor voltage can be returned to normal, and the engine will operate rich with no codes, because the ECU is happy. If the air leak is severe enough, the false lean condition cannot be corrected. At that point, the engine will operate rich but throw you a lean code - yes a lean code because that is what the ECU thinks the problem is. So, yes, replacing exhaust gaskets, provided one is leaking in the first place, can correct a rich condition.
To check O2 sensor operation with BUDS, hook up to the bike and access the bike’s information. Go to the Monitoring Tab at the top, and the ECM Tab at the bottom of the page. Look over the page for a second because it’s very busy. Down at the bottom area you should have a little green light to tell you when the O2 sensor comes on line. You might also have a text box area a little to the left of that for O2 sensor status. Go ahead and start up the engine. The text box will display the current Status as the sensor warms up and comes on-line, and you will get a green light if everything is OK. Give it some time, of course. This page will also give you a chance to observe MAP sensor readings and see if they make sense.
Do yourself a favor and get a service manual. 25 bucks. Good Luck.
https://canammanuals.com/product/20...air-and-maintenance-manual-master-collection/
