P2B88Intake Air O2 Sensor Circuit Bank 1
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Needs a drive cycle to confirm a fix
- How the car detects it
- P2B88 is the catch-all electrical code for the oxygen sensor that some turbocharged engines mount in the intake tract, behind compressor and charge air cooler, to judge how much exhaust the recirculation system is feeding back. Ford's patents describe this intake sensor as a heated wide-band element whose pumping current shrinks as recirculated gas dilutes the fresh charge. P2B88 is meant for a signal fault the module cannot sort into too low or too high, such as an open lead or a reading that keeps dropping out. No manufacturer documents P2B88 publicly; CARB requires every input used for emission control to be checked for circuit faults. Without the signal, EGR runs on a model or is switched off. P2B89 and P2B8A split the fault by voltage, heater faults are P2B8B to P2B8E.
- What you may notice
- Check engine light on
- EGR reduced or switched off, with slightly higher fuel use or knock-limited power
- Often no noticeable change in driving behaviour
- Likely causes
- LikelyCorroded or loose sensor plug, often wetted by charge air cooler condensate
- PossibleOpen or chafed signal wire between sensor and engine module
- PossibleIntake oxygen sensor element internally failed
- RareFault in the sensor input stage of the engine module
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Often possible to do yourself.Typical cost: €60 – €400
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.