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Home >> Subaru >> 2005 >> Forester XT, Automatic >> Repair and Diagnosis (Single Page) >> Engine Performance >> System >> Diagnostic Trouble Code (DTC) Detecting Criteria (H4DOTC) >> Diagnostic Trouble Code (DTC) Detecting Criteria >> DTC P0133 O Sensor Circuit Slow Response (Bank 1 Sensor 1) >> Diagnostic Method
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Diagnostic Method

Integrate the difference of faf in every 128 milliseconds and difference of "LAMBDA" value.

After integrate 1640 times (210 seconds), calculate the diagnosis value.

Judge NG when the malfunction criteria below are completed. Judge OK and clear NG when the malfunction criteria below are not completed.

Judgment Value 

JUDGMENT VALUE

Malfunction Criteria Threshold Value
parafca = td2faf/td2lmd where,
td2faf (N) = td2faf (n - 1) + d2faf (n)
td2lmd (N) = td2lmd (n - 1) + d2lmd (n) add up for a total of 210 seconds
d2faf (n) = (faf (n) - faf (n - 1)) - (faf (n-1) - faf (n-2))
d2lmd (n) = (lmd (n) - lmd (n - 1)) - (lmd (n-1) - lmd (n-2))
faf = main feedback compensation coefficient every 128 milliseconds
lmd = output lambda every 128 milliseconds
>/= 0.318

Time Needed for Diagnosis:  210 seconds

Malfunction Indicator Light Illumination:  Illuminates when malfunction occurs in 2 continuous driving cycles.