Thread: Duty cycle
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Old 07-30-2003, 08:09 AM
mbdoc mbdoc is offline
Join Date: Mar 1999
Location: Tucker, Ga USA
Posts: 12,153
Duty cycle OR Lamda(14.7/1) fuel mixture is designed to keep the engine from emitting excessive emissions. Open loop fuel mixture is important however there really isn't any spec for that type of setting anymore. IF you set the mixture too rich OR lean in open loop then the O2 sensor MIGHT not be able to bring the car into closed loop, or the system might go into FOM (fixed operating mode)

That is why MB suggests a duty cycle of 50% +- 10%
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