***** I have a 2004 Ford Focus ZTS 2.3L manufactured January 2004 with a persistent P0054 code for the last 6 months or so. The CEL initially turned on after two applications of catalytic converter cleaner in the gas tank. After replacing the B1S2 O2 sensor with a Bosh 15645 & resetting the code the P0054 code returned a day or so later.
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