Why so many Cats?

[Kim]

Thanks guys!
AFAIK it's not a FlexFuel engine, as I've seen nothing anywhere on the truck that says it is or might be. I'm not having any problems with them and wasn't planning on deleting any. Just curious as to why there needed to be 5 of them! As a perspective here's a few examples by decade of previous vehicles I owned:

74 AMC Matador Coupe 304 2bbl = no cat
82 Pontiac Trans Am 305 Cease-Fire Injection = 1 cat
94 Ford Thunderbird 4.6 SOHC = 3 cats
01 Ford Ranger Edge 3.0 = 5 cats = a meth addict's dream!

 

[Deiimos]

I didn’t count them, but was under mine yesterday welding the flange between two of the cats as it is rusted / separating and getting too loud. It’s better now, but I had a moment where I told myself it seemed like a lot of cats in the system.

Edit: I did finally count them out of curiosity, and it appears to be five like the OP's post / photos.

My 95 Lincoln Town Car has four last I recall.

 

[sgtsandman]

I suppose some of it has to do with the emissions standards it was built to meet (California vs 48 State). Some of it will be due to the engine in the truck. It may also be due to space considerations and more cats were needed to meet the emissions level they were looking for.

This is all a guess though.

My RWD 1998 with a 2.5 Lima only had one and my 4X4 2011 with a 4.0 has one on each bank. I can’t remember for sure but I think my 4X4 2019 with a 2.3 Ecoboost only has one. And none of them are California emissions.

 

[cbxer55]

My 98 Ranger 3.0 is a CA model. It has three iirc. One on each side and one large one in the back. My 2007 4.0 Mustang only has two, one on each bank. But the previous owner did some mods to it, not sure if it had one behind the Y under the vehicle. Doesn't now.

 

[Kim]

Normally, there is only one pre-cat each side of the Y-pipe and then one or two main cats after the Y-pipe. Your left side of the Y-pipe with the two cats kind of looks like it is not OEM. Are you sure it has not been repaired at some time?

I did find a few places selling the Y-pipe with cats. Here's one that has the cheapo wrinkle-bend pipes and 3 cats: