Hello I have a 2003 Buick century customs and my engine light came on I went to AutoZone and had a diagnostic done it read Error code P0135 H02-11 Bank 1 sensor 1 Heater circuit malfunction.. I had replaced the sensor 02 downstream but light still on a it's reading the same thing should I replace the upstream sensor also? Thank you
My car has 174000 miles.
My car has an automatic transmission.
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