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Test Point 7 - Oxygen Regulation Stop

TEST POINT 7 - Oxygen regulation stop - Fault code 1_23

Possible Causes, Elimination, Remarks
The oxygen regulator cannot operate in its control range owing to problems with mixture preparation, e.g. too lean because of additional air or too rich because of a sticking injection valve. The oxygen regulator then moves up to the stop position.

Test 1: Check CO level with running engine and connected CO tester. (between 0.4 - 1.2 %)

too lean: Check intake system for leaks, Test Point 21 - Intake System Leak

too rich: Test system pressure and injection valves for leaks, Test Point 20 - Fuel Pressure