1999 E150 5.4L
My Matco scan tool shows the following codes
p0305,p0306, p0308 That is miss fire on cylinders 5,6, and 8
p0401 insufficient EGR flow
p0402 excessive EGR flow
P0430 Catalyst system efficiency Bank 2 below threshold
P0174 Fuel system too lean bank 2

Have confirmed driver side lower catalytic is completely burnt and broken out, upper about half burnt. Have at this time put in temporary test pipe in place of both (don't want to ruin new cats before I figure out additional problem) and have emptied all further exhaust of parts and pieces of broken cat.
Engine has very little power, takes a full mile to get up to 35mph.
Nearly continual backfiring
Have checked spark plugs one at a time finding all plugs a perfect ashy white color with no breaks or problems except #7 which is slightly blackened (no build up, just colored)
With van running I can pull any single plug wire or injector wire and it causes NO further running issues.
Have replaced a couple of vacuum lines which looked dry rotted but made no difference in running.
Have been running Sea Foam for about 30 miles (distance to get van home)

Currently having some financial issues and can not afford to just throw parts at this (have lost 2 other vehicles in less than 6 weeks) I need real help figuring out where to start... Man I miss old Fuel and Spark trucks... I truly appreciate your expertise...

 

My apologies, duplicate post (first one said it couldn't post, assumed it didn't so posted again)
Here is a link to the other one
https://www.f150online.com/forums/v8...fire-more.html