P1131 said oxy sensor Bank 1 is lean where is it loctated on1998 Ford F 150 4.6l W

Question

Looking for the location of bank one heated oxy sensor

Answer 1

bank 1 will be on the passenger side 

start by checking for intake leaks, clean the mass air flow sensor with mass air flow sensor cleaner.

if you have not replaced the spark plugs do so 

check fuel pressure

if you still have the problem replace the air to fuel ratio sensor (oxygen sensor) on bank 1 sensor 1 (on passenger side exhaust manifold)