OBD-II code · Powertrain (generic, extended)
P25F7 AIR System B Incorrect Flow Detected
The second AIR system delivers measurably more or less air than expected. Often a partially blocked pipe, a worn pump, or a leak between pump and check valve.
Is it safe to drive with P25F7?
Usually safe for short trips, but don’t ignore it: the underlying fault can get more expensive over time.
Common causes
- Most likelyAir pipe partially blocked by carbon
- PossibleWorn pump impeller reduces flow
- PossibleLeak between pump and check valve
Repair at a glance
- Difficulty
- Hard
- DIY friendly
- Best left to a mechanic
- Typical labour
- 1.5–5 h
- Emissions test
- Likely to fail
- Parts involved
- Air Pump B, Air Check Valve, Air Flow Sensor
Related codes
- P25F4Turbocharger/Supercharger Boost Sensor C Circuit Low
- P25F5Turbocharger/Supercharger Boost Sensor C Circuit High
- P25F6AIR System B
- P25F8Turbocharger/Supercharger Bypass Valve C Control Circuit
- P25F9Turbocharger/Supercharger Bypass Valve C Control Circuit Low
- P25FATurbocharger/Supercharger Bypass Valve C Control Circuit High
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.