NOx Sensor 22790 8539R

BG 201191 (OE 22790 8539R): function on the vehicle

NOx Sensor 22790 8539R is supplied by BEST GROWTH under part number 201191, cross-referenced to OE 22790 8539R, as a direct-fit aftermarket nox sensors. In service it acts as the closed-loop feedback element of the SCR circuit: it tells the controller how much NOx is still leaving the catalyst, so dosing is trimmed up or down instead of running to a fixed map.

BG 201191 is built to the position defined by its OE application on a 12V electrical system in light commercial vehicle service on platforms from Peugeot, Citroën and Renault. Position, calibration and connector layout are part of the specification, so a part that physically fits is not automatically the correct part.

Cable length and connector keying are part of the specification. A cell with correct electrical output but the wrong lead length will not route to the OE bracket.

Fitment for Peugeot, Citroën and Renault and OE cross reference

BG 201191 replaces 2 OE references: 22790 8539R and 5WK9 6747, covering cross applications. Always confirm the number printed on the removed part, including any supersession issued by the vehicle manufacturer.

Recorded vehicle coverage for 201191 includes Peugeot, Citroën and Renault, typically on Trafic X82 / Master MK3 1.6 dCi. Coverage lists are a starting point for identification, not a substitute for checking the OE number on the vehicle.

Where several OE numbers appear against one BG reference, they are supersessions or regional variants of the same specification. Ordering by 22790 8539R and quoting the number on your part lets our technical team confirm the variant before despatch.

Symptoms that lead to replacing 22790 8539R

These complaints bring a vehicle in with the Peugeot and Citroën nox sensors under suspicion. None of them prove BG 201191 has failed on its own, which is why the checks below matter before a replacement is ordered.

• DEF over-consumption with no visible leak
• torque derate or speed inducement with a full, in-spec DEF tank
• no communication with the sensor control module after a cold start
• sensor value frozen at a fixed number once the exhaust warms up
• dosing shut-down after a few minutes of steady-state running

Checks before fitting BG 201191

Aftertreatment faults are usually system faults. Working through these checks prevents a repeat failure after the new nox sensors is fitted.

• Check for a pending software or parameter update for the sensor control module on that platform.
• After fitting, run the manufacturer's adaptation or relearn so stored efficiency counters reset.
• Compare upstream and downstream NOx readings warmed and under load — idle values prove nothing.
• Confirm supply voltage, ground quality and bus termination before condemning the sensor module.
• Inspect the harness for heat damage and the connector for moisture and green corrosion.

Quality, packaging and ordering 201191

BG 201191 is manufactured and tested to aftermarket replacement standards, with electrical, leakage and functional testing carried out before packing on the 12V specification. Bulk and retail packaging, private-label cartons and customer-specific labelling are available for distributors and workshop groups.

Send OE 22790 8539R or the number printed on your part, the engine code and the vehicle identification number with your enquiry, and our technical team will confirm the correct reference, current stock position and lead time before you commit to an order.

Frequently asked questions

Does BG 201191 replace OE 22790 8539R?

Yes. BG 201191 is listed against 22790 8539R and 5WK9 6747. Confirm the number printed on the removed part and any manufacturer supersession before ordering.

Which vehicles does BG 201191 fit?

Recorded coverage includes Peugeot, Citroën and Renault. It is supplied as a direct-fit aftermarket nox sensors on 12V systems. Adaptation, reset or relearn procedures required by the vehicle manufacturer still apply after installation.

Does this fault code always mean the nox sensors has failed?

No. Exhaust leaks, wiring and connector damage, reductant quality, dosing performance and upstream engine faults can all produce the same codes. Validate those inputs before replacing BG 201191.