Question about installing an X-Pipe.

johnny_261

Member
Dec 10, 2006
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I just bought a UPR Catted X-pipe and have never installed one before...I had a question regarding the EGR Air Tube.

In the installation instructions it says to "Disconnect the air tube coming from the emissions pump and cap off with a ¾” rubber end cap and clamp".

Where did this pipe go before and is there any problems with just capping it with a rubber end cap?

Any info you can provide on the subject would be really helpful.

Thanks.
 
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Okay, prepare for a science lesson. The smog pump that came as stock emissions equipment on your mustang is not dead weight, nor was it put there for aesthetics. Automotive engineers are pretty intelligent. If you're keeping your smog equipment, the thermactor air pump pumps fresh air into the catalytic converters to aid in the catalyzation process. A three part reaction takes place in the catalytic converter, and the presence of oxygen is required (this is the role of the thermactor air pump).

A) Reduction of nitrogen oxides to nitrogen and oxygen: 2NOx → xO2 + N2
B) Oxidation of carbon monoxide to carbon dioxide: 2CO + O2 → 2CO2
C) Oxidation of unburnt hydrocarbons (HC) to carbon dioxide and water: CxH2x+2 + 2xO2 → xCO2 + 2xH2O

You'll notice above that oxygen is required for the chemical reactions listed. Without air supplied from the smog pump, the catalytic converters will overheat and eventually clog and fail, therefore severely increasing exhaust gas backpressure and limiting performance. You bought a catted X pipe, therefore you'll need to hook the air pump up to keep your cats alive and help pass emissions. I've heard that performance "high-flow" catalytic converters require less oxygen to operate, but this is heresay and hasn't been confirmed. Play it safe and hook the smog pump up.


Sorry for the novel, I was bored. :D
 
Does the UPR pipe have the bung to hook the air pump pipe up to? If it does...connect it. If it does not, cap it off.

The air pump is to provide fresh air to the cats because certain types require oxygen to help the process. Since the pxygen is burned off when the engine runs, it must be provided through an air pump.

Modern cats do not require this, so the air pump can be eliminated in most cases. However, some companies still use the old style cats. In taht case, i just simply say that if the pipe has the provision for the air pump to be hooked up...then use it. If it doesn't then don't worry about it.

I actiually removed my smog pump quite a while ago, and now have reason to suspect my stock h-pipe is clogged. Now i'm in the market for the Magnaflow catted pipe
 
Is there an echo in here? Just kidding, Mike. :nice:


I think was typing while you were as well..so i didn't see your post.


MagnaFlow 93338 - MagnaFlow Direct-Fit Catalytic Converters - Overview - SummitRacing.com

Anyway, was shopping for my pipe and noticed the magnaflow pipes also use the oxidizing style cats.

So looks like i gotta put my smog pump back on either way....and i don't even have emmissions anymore. :shrug:


Supposedly the Magnaflow spun-metallic cats do not require oxygen, however from what I can see, they do not offer them with an H-pipe...but only as aftermarket weld-on cats.
 
Thanks for the detailed info guys! I really appreciated.

I haven't received the part yet, but wanted to familiarize myself with the install before I get started with it.

The instructions say to cap off the air pump pipe, so I'm guessing that it doesn't have the bung. I'm also guessing based on the info that you've provided that this type of cat is okay without it, so I should be fine with emissions then?

Thanks for the help! You guys are awesome!
 
Does the UPR pipe have the bung to hook the air pump pipe up to? If it does...connect it. If it does not, cap it off.

The air pump is to provide fresh air to the cats because certain types require oxygen to help the process. Since the pxygen is burned off when the engine runs, it must be provided through an air pump.

Modern cats do not require this, so the air pump can be eliminated in most cases. However, some companies still use the old style cats. In taht case, i just simply say that if the pipe has the provision for the air pump to be hooked up...then use it. If it doesn't then don't worry about it.

I actiually removed my smog pump quite a while ago, and now have reason to suspect my stock h-pipe is clogged. Now i'm in the market for the Magnaflow catted pipe

My after market cat didn't come with the nipples to attach the hose to. So I just let it pump into the air. :shrug: And the smog pump just siezed about a month ago. So now Im all good! :D
 
How hot will the x-pipe get? I was thinking about painting it black with one of those duplicolor high heat paints that are suppose to be good up to 1200F. It rains quite a bit where I live so I'm worried about corrosion...