Safe Mode

[Andre]

What are the factors which cause the ecu to put the car in safe mode?

[KiwiTT]

To low octane in fuel ?

[Roadrunner]

Could be one or more of a number of factors ... the ECU responds to any input that is outside of the tolerance limits for that particular input by dropping the boost to a safe level to minimise any potential damage.

Causes could be faulty or contaminated air flow sensor, lambda sensor, poor quality or low octane (as KiwiTT said) fuel, or other sensor that has gone faulty and is giving duff information to the ECU. AFS is more easily contaminated if you have replaced the OEM panel filter with something that filters less (induction kit, for example); lambda sensor can be contaminated by poor quality fuel, octane boosters (personal experience with my Legacy RS-B) or other fuel additive. Could be a number of things, but the above are the most likely, so I'd start with them.

Brian