Cat. question

[Johnny Wayne]

My bronco has only 1 cat on it. now the question is the cat I have has the air tube on top. Well stupid me ordered one that did not have the tube on it. Is the tube something I can close off and put the other cat on or will that give some code or something like that.

Let me know thanks.

1990 Bronco, 5.8, Bassani header 2 1/2, and then 3 inch cat back with Cherry Bomb

Thanks

 

[Justshootme84]

You can look if the current cat has the tube hooked into your headers, but I doubt it.

 

[Johnny Wayne]

You can look if the current cat has the tube hooked into your headers, but I doubt it.

so you are saying if it is not connected to the header than it will be fine to cap?

thanks

 

[Justshootme84]

Yes, since it prolly ran to the stock manifold on one side.

 

[Broncobill78]

Doesn't that tube on the cat connect to the air-pump ? On My other Bronco's w/cat's that was the supply line for the air input from the air-pump. I don't think it will throw any codes but the emissions may be off without the air-injection from the pump.

 

[Justshootme84]

BB78, you're probly right.I was thinking the line runs to or along the passngr-side exhaust manifold, and does have a hose going to the AIR or smog pump. Not going to affect the motor, just the emissions.

 

[Jersey]

Didn't some of them have a crossover manifold that ran to the back of each head? If it does you can just take it off and put plugs in the holes. I can't remember for sure but I could have sworn i saw that setup a few years.

 

[Justshootme84]

JW, I'll see if I can find a diagram for you. In the meantime, you might look at Miesk5's Homepage. The link is in the Tech Articles forum, JSM84

 

[Johnny Wayne]

JW, I'll see if I can find a diagram for you. In the meantime, you might look at Miesk5's Homepage. The link is in the Tech Articles forum, JSM84

OK Thanks

 

[Justshootme84]

Here's a couple linksthat may help, or might confuse you further:

http://www.broncolinks.com/index.php?index=147

Scroll through until you read the emissions info and continue looknig up to nearly the last page.

Here's a simpler diagram of the cat tube up to the y-pipe from the AutoZone online manual:

http://www.autozone.com/az/cds/en_us/09008...irInfoPages.htm

http://www.autozone.com/az/cds/en_us/09008...irInfoPages.htm

There should also be a diagram or two of the upper section. Prolly just easier to look on your Bronco, and see if the stock tube is still hooked up, or was removed when the headers were installed. JSM84

 

[Broncobill78]

Didn't some of them have a crossover manifold that ran to the back of each head? If it does you can just take it off and put plugs in the holes. I can't remember for sure but I could have sworn i saw that setup a few years.

Yup, they sure do. My 88' has that (not that it's connected to anything, just sits there burning up wiring & plugs while spewing a cloud of smoke every time I blip the throttle). Now I'm not sure just how this all plays out. If the Cat that was ordered DIDN'T have a provision for an air intake then perhaps it was a newer cat that *doesn't* need air injection (or maybe an older one that didn't yet have the provision) I think the only way to tell will be to sniff it after the fact. It really may not make a difference, the cat *should* catch & convert most of the emissions & if it doesn't have an air-tube then it wasn't intended to be air-injected. IF this combo gets you thru your State Inspection then you should be able to remove the air-pump & replace it with an idler pulley and gain a few ponies.

 

[Johnny Wayne]

Thanks for the help. I will have to get under the hood and find out where the tube goes.

Thanks.