Possible causes
– Faulty HO2S21
– Fualty Mass Air Flow (MAF) Sensor
– HO2S21 harness is open or shorted
– HO2S21 circuit poor electrical connection
– Fualty Mass Air Flow (MAF) Sensor
– HO2S21 harness is open or shorted
– HO2S21 circuit poor electrical connection
Symptoms
– Engine Light ON (or Service Engine Soon Warning Light)
AUDI Technical Service Bulletins for P1148 code
2002 AUDI A4 ENGINE AND ENGINE COOLING:ENGINE
2002 AUDI S4 ENGINE AND ENGINE COOLING:ENGINE
2002 AUDI TT ENGINE AND ENGINE COOLING:ENGINE
2003 AUDI A4 ENGINE AND ENGINE COOLING:ENGINE
2003 AUDI S4 ENGINE AND ENGINE COOLING:ENGINE
2003 AUDI TT ENGINE AND ENGINE COOLING:ENGINE