If it helps at all, my truck which is a 2000 ZF6 built in December of 1999 did NOT have a cat on the OEM exhaust.

 

My e99 handshaker does have a cat, but I seem to recall other e99 owners posting no cats in other threads. Really, the only way the OP can determine what came on his truck is to read the emission sticker on the valve cover. It's on the passenger side valve cover on my F250, can't say for sure if it's the same for vans. And it's practically impossible to read with the IC pipe installed. I know vans don't have intercoolers, but I'm sure there's something blocking your view!

Edit: Someday I guess I'm gonna be looking for another 1999 pass valve cover ...

 

"I believe all E99 trucks came with cats too, and most hand-shakers from the L99 and up rigs will have cats too. Can't remember the rhyme and reason for it, but they did."

From what I have been able to glean is that mid '99 on had no CAT as long as it was an auto trans. The manual trans versions had a bit more HP and required a CAT for some reason. I don't think that the HP difference is all that much but I guess there is some threshold requirement. But as SOUS points out, there are no absolutes in life.

 

Hey everyone sorry to bring back an older thread but i finally did a 4 inch exhaust on the van. Its a diamond eye turbo back. Sounds great and helped uncork the truck a bit. I want to get a tuner and i think im leaning towards hydra. Heres what im looking at

https://www.ecddiesel.com/power-hung...-for-ford.html

 

Do you have EGT gauge yet? Don't forget that your E model does not have an intercooler on it (unless you found a way to squeeze one in there).

 

No the egt guage is also on my list. Truck is stock minus the exhaust.

Manufacture date is march 1999. Does that make this an early 99 as opposed to a 99.5? Or does it not matter on the vans?