[jar73186]

I know I read this somewhere on the forum but I can't find it through the search. Correct me if I am wrong but the stock cats on a '94 with a 351 are a two part system (Oxidation-Reduction). Does anybody know if you can replace that with a single high flow cat.
Thanks
adam

 

[imlikeojnow]

yes you can. just switch the two with a high flow cat

 

[Bronco Rob]

Yup, i run out of one high flow cat to a "y" pipe to duals out the back (which i don't suggest). If your going to run duals, exit them out in front of the rear tire, that way you can use your back window.

 

[jar73186]

All right that sounds good. One more question.What is a good high flow cat that won't break the bank?
Adam

 

[Big_Sean]

from what i am told, dont quote me on this, but ive been to exhaust shopes in missouri, kansas and nebraska(dont ask) but in missouri and kansas it is illeagal to alter the emmisions equipment if the vehicle is less than 26 years old, but you can run 2 high flow, but it cannot be reduceded from 2 to one, just my .02

 

[Saurian]

It's a federal crime to remove catalytic converters.

That said, mine are completely gone.

Go on Ebay and look for "Catco" high flow catalytic converters. They're like 50-60 bucks each. You could run two of them and run true duals still, or Y into one then dual out again, or just run a single exhaust pipe out before the tire. Your call. If you live in an emissions state that does a visual inspection, do two of them. If you have a sniffer but no visual, you could do just one and probably be cleaner then you had been in years. It's all your call. Here in Iowa, no visual or sniffer so I'm good unless they change that.

 

[monkeyhouse]

just move to texas, out in the sticks, they dont care if you run open headers.

 

[jar73186]

Kansas only inspects when you purchase the car. So emissions aren't a problem. I know that I keep asking questions but how difficult is it to replace with one cat. Do i just have to cut and weld or is there something with the emmission controls in the Bronco that have to be changed.

Thanks for the Help
Adam

 

[topfisherman]

You can check out here: Clicky

They have full replacement y-pipe and it is easy to replace, unless a bolt on the exhaust manifold breaks from rust.

 

[jar73186]

Correct me if I am wrong, I need the air hose. Do i need the O2 bung?

adam

 

[coloranger]

It is not illegal to "replace" cats, only to completely remove them. And you can do a two to one as long as you meet the standards set. Also if you want to run true duals get a pair of 4 cyl cats. Cats have to get up to a certain temp to work correctly.

 

[94_bronc]

i did it and the whole system cost just over $300


http://www.fullsizebronco.com/forum/showthread.php?t=46106

 

[jam0o0]

you need the O2 no matter what or it will turn on the check engine light. the cat co cat's are great. i have one on my truck. replaced the two factory ones with one catco. now it has HALF the emitions on the sniffer test. one thing though it's not a cut and replace. the first factory cat is dual in so you will need some kind of Y pipe in front of the cat. and catco makes a cat with the air injection pipe already on it. but the a-holes who built my system didnt use it. they make their own. badly.

 

[topfisherman]

Correct me if I am wrong, I need the air hose. Do i need the O2 bung?

adam

If you get the full replacement y-pipe from the link I posted, it comes with a O2 bung welded in right between the pipes jut like stock, and it comes with a new air hose to replace the old one.