I had the diagnostic code read at a local Autozone and it reported both
a P00171 and P00174 error, which means all 4 O2 sensors (bank1 and 2,
before and after) are bad (running too lean). Can this be a false
reading? How can all 4 sensors go out at exactly the same time? Is that
Someone suggested replacing the fuel cap on some fords sometimes fixes
the problem....any comments on that?
Another problem I have is understanding the terminology.... Looking at
a diagram printout they had given me at Autozone, it shows 3 BEFORE
sensors (B1S1, B2S1 and B1S2) and only 1 AFTER sensor (B1S3). I
cannot see the 2 before and 2 after split/designation some online auto
part stores are referring to. I don't know which replacement parts I
should order, 2 before and 2 after sensors, OR, 3 before and 1 after
Will the check light turn off automatically when the faulty sensor(s)
is replaced or does it need to be electronically reset?
Any help will be much appreciated!