Good move, sending off the ECU! When you refit it, you'll need to run the engine without touching the throttle until it shows three bars on the temperature gauge. This will reset the throttle position sensor.
Also note that the bike may feel odd for the first couple of hundred miles while the ECU relearns the auto-adaptive parameters. Don't worry, it'll soon settle down.
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Now you've removed your lambda sensors, it's advisable to protect the exposed connectors from moisture either with some silicon grease or with some proper blanking plugs.
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Don't forget to let us know how it feels once you've done the ECU and spring.