BMW E90 N43 NOx sensor and fault code 30EA
BMW E90 N43 fault code 30EA, what does it mean?
30EA means sulphur (sulphate) has built up in the NOx catalytic converter and its storage capacity has dropped. The cause can also be a faulty NOx sensor or its wiring. Short city trips increase sulphur build-up.
What helps if the N43 NOx catalytic converter is clogged with sulphur?
A longer, brisk motorway drive starts the catalytic converter cleaning, and fuel consumption and codes may return to normal. If the NOx sensor is faulty, the cleaning will not start, so the sensor has to be fixed first.
How does a faulty NOx sensor show up in an N43 car?
The car runs permanently on a normal mixture instead of lean mixture, which raises fuel consumption. A sensor fault does not usually cause rough running. Cleaning the sensor surface did not fix the fault permanently; the code came back.
What is done when the NOx sensor is replaced?
The type number of the new sensor and the type number of the electronic unit must match; one sensor part number is 11787587130. After replacement the fault codes are cleared with a diagnostic program and the state of the catalytic converter cleaning is checked.