A common track support comment from teams when reviewing their logged data is that they believe their lambda sensor has failed due to it reading high values (5.00) during closed throttle decelerations.

This observation is particularly common when data is being compared between sessions which were were run using both the dry and wet engine maps.

This behaviour however is correct and does not mean that you have a faulty sensor.
The Renault Clio Cup Car's engine map utilises the Pectel 'Over-Run Fuelling' strategy - this is where a fuel cut is applied to the engine when it is decelerating and therefore no longer needs to produce torque, thus improving the car's fuel efficiency.

There are configurable engine speed thresholds which enable the over-run fuelling strategy when the current engine speed exceeds these threshold speeds. These speed thresholds are calibrated against engine temperature and also differ between the dry and wet map. 

The channel 'EN_Inj_Time' shows the ECU's injection time, if this is set to zero during closed throttle deceleration then this usually means the over-run fuelling strategy is active and therefore you can expect your lambda sensor value to read high (lean).
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