Generally, most electronic components mounted on the Subaru WRX have proven to be extremely reliable in service, with one notable exception. You can also check the performance of Subaru wrx 0-60 times via online search.
Flash 02 and later equipped with air mass sensors have an air temperature sensor construction that further improves the accuracy of the sensor.
Air mass sensors mounted on the Subaru WRX Version V and VI cars are a bit on the fragile side, especially when used with aftermarket air filters. This type of air mass sensor uses a sensing element "hot film".
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Subaru ECU monitors the amount of cooling air effect is traversed by the heated sensing surface and from this data can be calculated with a high degree of accuracy, the actual weight of the intake charge.
Less desirable is the effect of particulate contamination and oil residues can have on the sensor operation. Subaru WRX may be sensitive, even small amounts of dust or oil may be sufficient to reduce the output of the sensor up to 30-50%, which seriously affects the engine operation.
Proper operation can sometimes be restored by carefully cleaning the sensor element with an electronic contact cleaner. However, do not use a contact lubricant as it will cause contamination problems of the worst sensor.
Cleaning is not always successful, because these sensors do not suffer cumulative damage. Professional repair shops will make a special point of checking this part during routine maintenance.