The wideband oxygen sensor's pump cell circuit is open. Fuel control loses its main feedback signal.
P2237 — also written P2237, P 2237, 2237 — is the OBD-II code for o2 sensor positive current control circuit open (bank 1, sensor 1). Same code, same fix: this page covers every spelling of it.
P2237 is a emissions fault code, typically costing £120–£450 to put right in a UK garage.
What causes P2237?
- Failed wideband O2 sensor
- Broken wire or corroded plug
- Sensor damaged during exhaust work
- ECU driver fault
How P2237 is fixed
- Inspect the sensor connector for corrosion and heat damage
- Replace the wideband sensor with the correct part number
- Repair the loom
P2237 repair cost in the UK
Most P2237 repairs land between £120–£450 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 P2237?
Yes, but expect poor economy and rough running.
Urgency: medium.
What P2237 is telling you
An emissions code means a self-test run by the ECU came back outside its allowed window. That test compares what the engine was asked to do with what the sensors say happened, so a sound exhaust system with a tired sensor throws the same code as a genuinely blocked one.
On P2237 specifically — o2 sensor positive current control circuit open (bank 1, sensor 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 P2237 is diagnosed properly
Each of the known causes is ruled in or out in cost order, cheapest and most likely first. On P2237 that means working through them like this:
- Failed wideband O2 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.
- Broken wire or corroded plug — checked with the loom flexed and the engine warm, because a wiring fault that is intermittent when cold shows itself under heat and vibration.
- Sensor damaged during exhaust work — 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.
- ECU driver fault — checked for outstanding manufacturer updates before any hardware is touched.
An hour of diagnostic time on P2237 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 P2237
- Inspect the sensor connector for corrosion and heat damage
- Replace the wideband sensor with the correct part number
- Repair the loom
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 P2237 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, P2237 typically lands at £120–£450 all-in at an independent garage in the UK — main-dealer quotes for the same job usually sit above that.
Getting P2237 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 P2237 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.