This truck got me stumped fist was pulling code for cat converter wich was bad replace that and now pulling up code p0340 and p0102 .I have changed the mass airflow sensor and camshaft sensor after reset cel comes right back on any help would be gratefull

What engine is in it?

Its a 5.7

The p0340 could also be caused by the crankshaft sensor. From what i found you should check the wiring and make sure theirs no breaks. For the p0102 could be bad o2 sensor or sensors.

check to see if you get the 12v on the pink to the maf and cam sensor(in dist)