Why would I have 2 cat converters on my 87 bronco II?
It an automatic trans. and 4X4 2.9
thanks
Rick

 

Ford commonly puts two converters on its vehicles instead of "one." From what I've been able to gather, the catalytic converter system actually has two stages: a "reduction stage" and an oxidative stage. "Single cats" and aftermarket converters combine both stages into one unit. For some reason, Ford likes to separate the two stages into separate units.

 

so if i cut the second cat off what will that do because i allready put custon exhaust on my truck and when i did that i cut the second one off?

 

Unless I was wrong, it means you are running with 1/2 a catalyitic converter. Probably won't effect how the engine runs. But, if the EPA gets wind of it, they might be less than pleased. If you have to submit to emissions testing, you'll probably fail next time around. It's technically illegal to remove/disable such emissions equipment.
Double check my information, and then fix it right if it needs to.

 

well i have no emmissions or safety inspection in my town and your most likely right but it sounds like a beast without it hehehe

 

As I understand it, even if you don't have to submit your truck for periodic testing, it's still against federal law. You just have a better chance of not getting caught, because no one's checking your truck.

 

im not to worried about it

 

The upper catalytic converter is usually referred to as a "light off" converter, and merely aids in the lower main converter in warming up to operating temperature more rapidly to help reduce cold-start emissions. The upper converter starts burning off the hydrocarbons in the exhaust, which in turn raises the exhaust temperature. The lower converter contains both the reduction and oxidation stages in one unit.

You can safely remove the upper converter and still pass emissions so long as you allow the engine to warm up 10 minutes or so before taking the test. Most inspectors have no clue what cars are supposed to have more than one converter, and as long as they can find one of them, you'll pass.

Bart

 

In some BII's they used the cat convertor up front and in the rear they used what is called a resonator along with the muffler.

 

my b2 has 2 cats up front, then a muffler, then a resonator. Wonder what
good is the resonator anyway?

 

in my 90 BII i went over 85 with the stock resonator on it and the welds busted on it. you can purchase a tailpipe that is long enough so you don't have to put the resonator back on it. the only thing it helps to do is lower the noise, so without it it sounds pretty good. kinda between a 4wheeler and flowmaster (more toward 4 wheeler). in new orleans it's not easy to find one so i just put on the longer tailpipe.


and the dual cats ARE there for an oxidation - reduction reaction (red-ox reaction). without the second one for oxidation you are letting out a ton of CFC's into the air (probably more than are associated with freon (spell?). if you have the room for it i would put it back cause it doesn't smell too good either

 

hehehe it may smell but it sounds great plus who needs an ozone to survive just kidding im planning on just puting on a $50 catco catalic converter there high flow and both stages in one box