Using NOx emulator NOXEM 402

How to use the NOx sensor emulator NOXEM 402

  1. Replace the existing NOx sensor to NOx emulator
  2. Perform service procedure ‘’Reset adaptation values and versions (encoding)’’ using ISTA D/+. This procedure will:
    1. clear adaptations of NOx sensor;
    2. clear status and profile of NOx catalytic converter;
    3. clear all old adaptations of the engine.
  3. Create new adaptations: re-adaptation of the engine



  • After installing and coding procedure of NOXEM, the positive effect is not reached immediately – it takes some time. First driving sessions after replacing the sensor may be with increased engine unevenness – the engine will measure the performance of each cylinder in different driving conditions: it will restore correct adaptations.
  • Some specific adaptations are performed only in conditions of even load and RPM. That’s why it is so important (after installing and coding of NOXEM), in first driving sessions (also after creating the initial adaptations, as described below) to allow the engine warm up in idle, drive as smooth as possible and with longer driving sessions. In such way, the engine will reach even performance as quickly as possible.
  • Immediate symptom, that the installation of NOXEM was successful: after new adaptations are completed, the engine (again) runs in Stratified charge when driving evenly – fuel consumption is decreasing.
  • In the initial stage, after installing NOXEM the engine will intensively create adaptations for exact driving conditions: most often it will switch to Homogeneous mode. It is normal and very typical for this engine – adaptations (also smoothness measurements of cylinders) are performed for each mode – Homogeneous, Homogeneous lean, Stratified charge – separately.
  • If in any of performance modes the engine runs with increased vibration (it feels like a diesel engine) – allow the engine run in this mode for some time (5 .. 10 min). MSD87 will identify unevenness and will immediately start to eliminate it.



Replacement of NOx sensor

  1. Take off the plastic shields in the middle area of passenger side floor;
  2. Disconnect the NOx sensor data cable;
  3. Unscrew two M6 screws;
  4. Unscrew the probe of NOx sensor, using 22 mm tool;
  5. Screw in the probe of NOx emulator;
  6. Fix NOx emulator, using two M6 screws;
  7. Draw the NOx emulator probe, using 22 mm tool with force 10 .. 30 Nm;
  8. Connect the NOx emulator data cable;
  9. Secure the plastic shields (protection cover) back in place.


Encoding procedures using ISTA D/+


1. Start new session in ISTA D/+, perform the identification of vehicle and a test;


2. If errors relating NOx sensor or NOx converter are stored, perform Test plan and follow instructions on the screen (confirm replacement of damaged components and clearing of adaptations);


3. Clearing of old adaptations:

a) Select Vehicle management/Service function menu;

b) Press ‘Power train’;

c) select ‘Engine electronics, quality control valve’;

d) select ‘Adjustment functions’;

e) select ‘Clear adaptations’, press Start search button

f) select ‘Clearing of adaptations (encoding)’ option, follow instructions on the screen

Note: for different ISTA D/+ versions enumeration of the menus may slightly differ


4. Re-adaptation of the engine. Flywheel adaptations

a) turn on the engine

b) accelerate till 100 .. 110km/h on even road

c) switch the 4th gear (for automatic transmission – in manual mode)

d) release the accelerator pedal, brake with the engine (don’t press brake pedal) at least 10 seconds

e) repeat b to d three times

e) stop the car, switch off the ignition, takeoff the key

f) wait, till the lighting of start/stop button turns off


4. Re-adaptation of the engine. Fuel mixture adaptations

a) start the engine

b) allow the engine to run idle for 5 minutes

c) perform the driving session with even speed 60 .. 90km/h; 5 .. 10min

d) repeat points b & c for several times


Re-adaptation of the engine, using ISTA D: detailed information