Possible Causes
WARNING: This page is about a different car, the 1996 Volvo 850. However, it is still accessible from the selected car via links, so may be relevant.
If DTC 442 (PAIR flow too high) and EFI-446 (PAIR valve leakage) occur together possible causes are:
- Leaking PAIR system valve
- Defective PAIR system solenoid valve
- Air leakage in the exhaust system
If DTC 448 (PAIR pump flow too high) is stored together with the above DTC, the following will also apply as possible cause:
- PAIR pump runs continuously
- Air leakage in the exhaust system
- Damage/hole in the hose between PAIR system pump and PAIR system valve