It could either have a gasoline engine or a diesel engine
The 2013 Ford F-450-Super-DUTY runs on diesel.
The 2010 Ford F-450-Super-DUTY runs on diesel.
The 2011 Ford F-450-Super-DUTY runs on diesel.
The 2015 Ford F-450-Super-DUTY runs on diesel.
The 2014 Ford F-450-Super-DUTY runs on diesel.
The 2008 Ford F-450-Super-DUTY runs on diesel fuel.
The 2009 Ford F-450-Super-DUTY runs on diesel fuel.
The 2012 Ford F-450-Super-DUTY runs on diesel fuel.
if your 1997 super duty is a diesel there is no catalictic converter if it is gas, then it is in the exhaust will look just like a muffler
between 0 and 18mpg
36mm