The NOx sensor is alive but its readings do not make sense against the rest of the emissions data.
P2202 — also written P22O2, P 2202, 2202 — is the OBD-II code for nox sensor circuit range/performance (bank 1). Same code, same fix: this page covers every spelling of it.
P2202 is a emissions fault code, typically costing £250–£1000 to put right in a UK garage.
What causes P2202?
- Aged or contaminated NOx sensor
- AdBlue dosing fault
- Exhaust leak upstream of the sensor
- Underlying EGR fault
How P2202 is fixed
- Check for exhaust leaks first
- Verify AdBlue dosing and quality
- Replace and code the NOx sensor
P2202 repair cost in the UK
Most P2202 repairs land between £250–£1000 including parts and labour. The spread is wide because the cheap fix (a sensor, a hose, a leak) and the expensive fix (a major component) throw the same code — which is why a proper diagnosis before parts are bought saves the most money.
Can you drive with P2202?
Yes, with reduced power on some models.
Urgency: medium.
What P2202 is telling you
Emissions-related codes exist so the car fails its own internal audit before it fails an MOT. The ECU only knows what its sensors tell it, and a lazy sensor, a chafed wire or a leaking pipe will all read as an emissions problem.
On P2202 specifically — nox sensor circuit range/performance (bank 1) — the stored code records the moment that check failed, not the moment the part gave up. That gap is why two cars with the same code can need completely different repairs.
How P2202 is diagnosed properly
Each of the known causes is ruled in or out in cost order, cheapest and most likely first. On P2202 that means working through them like this:
- Aged or contaminated NOx sensor — compared against live data and a known-good reference before it is condemned — a sensor reading the wrong thing accurately is a different fault from a dead one.
- AdBlue dosing fault — confirmed with live data before any part is bought.
- Exhaust leak upstream of the sensor — compared against live data and a known-good reference before it is condemned — a sensor reading the wrong thing accurately is a different fault from a dead one.
- Underlying EGR fault — confirmed with live data before any part is bought.
An hour of diagnostic time on P2202 routinely saves more than it costs, because the alternative is buying the most expensive part on that list and hoping.
The repairs that actually clear P2202
- Check for exhaust leaks first
- Verify AdBlue dosing and quality
- Replace and code the NOx sensor
After the repair the code is cleared and the car is driven until the relevant readiness monitor completes, rather than handed back as soon as the light goes out. A code that has only been erased will come straight back on the next drive cycle.
What happens if P2202 is ignored
The car will usually keep going, but the fault will not clear itself and the related monitors stay incomplete — which matters if an MOT is due, because a car that has not finished its emissions self-tests can be refused.
For reference, P2202 typically lands at £250–£1000 all-in at an independent garage in the UK — main-dealer quotes for the same job usually sit above that.
Getting P2202 looked at
Bob's Mechanical Repairs is an independent garage in Birnam, Dunkeld, Perthshire, with 32 years of Bob's experience on the tools. If P2202 is showing on your car, bring the scan results with you — we will read the live data ourselves, tell you which of the causes above it actually is, and price the repair before any work starts.