In 1973, a new model was offered, the F350 SRW (single rear wheel) pickup. These were a new heavy duty pickup with contractors and camping enthusiasts in mind. The trucks rode on a longer wheel base chassis but were the same overall length as an F250 pickup. If you ordered the Campe...
be an EGR problem that was throwing an "insufficient flow, EGR" code. In any case, after 3 visits to non-Ford 'tune-up' shops who went after the EGR valve, I read up on the Serious Explorer message board and determined that it was the EGR differential sensor ( something like that)....