My 01 Dakota with a 4.7, 5 started runnin like total ***.. well my old boss had a mechanic shop of his own for about 14 years, I gave him the symptoms, he said it sounds like your cats clogged. So I cut the Flowmaster off the back, along with the curved piped( it went over the axle) and took a 5/8 piece of rebar and a 3 lb baby Sledge and Reamed that catalytic converter out. Check it out on the Veterans Expressway flat-footed that mother I heard a big loud boom truck got loud then but it opened it right up unclogged the heck out of that! That was during the last recession and people were stealing copper off of houses from air conditioners and stealing catalytic converters I did not care about that I just wanted my damn truck to run properly