How many O2 sensors would my 2008 Ford F250 5.4 V8 have?

There would be 2 oxygen sensors before the catalytic converters and 2 after them. Diagnostic testing is essential in monitoring oxygen sensor specific performance on a data stream via a diagnostic tool to see if one is not responsive compared to the others. Trouble codes that can seem to relate to oxygen sensor failure could actually be set off by many other things.