Smog pump questions

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Dec 27, 2002 | 05:44 PM

jrs_big_ford_f150

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From: Dededo, Guam

Smog pump questions

[updated:LAST EDITED ON 27-Dec-02 AT 06:47 PM (EST)]What exactly does the smog pump do?

Can I get get rid off it and put a pulley in its place?

Is it worth my time and trouble to get rid of it?
Keep in mind that i don't have to pass any sort of emissions regs.

Anyone here ever go throughthe trouble of ripping one out?

thanks for any info.

Dec 27, 2002 | 05:53 PM

steve83

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From: Memphis, TN

Smog pump questions

All it does is blow air into the exhaust to burn excess gasoline (reducing HC emissions). It has NO effect on how the engine runs except that it needs probably 1/2hp to turn it, which isn't noticeable. There's no reason to disable the system if it's working, and several good reasons to fix it if it's not. Even if you decide to delete the system, it's still cheaper to use the pump as an idler pulley.

Dec 27, 2002 | 10:50 PM

heathdaily

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From: kansas

Smog pump questions

[updated:LAST EDITED ON 27-Dec-02 AT 11:52 PM (EST)]I am under the impression, and correct me if I'm wrong, that pulling the pump off of a 4.9 could cause the O2 sensor to misread. This is because it puts in air both at the cat, and into the head. The air going into the head would comprise part of the exhaust flow past the O2 sensor. Removing that air would cause a change (how much I don't know) in the percentage of gasses in the exhaust. This should be fixable with a custom chip. Possible exceptions, not all 300's use heads with air injection, maybe ??????

Dec 28, 2002 | 07:06 AM

ftwfred

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From: Kentucky

Smog pump questions

YES!!! You are exactly right!!!Pull the air pump off ANY engine with an O2 sensor and yer askin for trouble...

the cat also needs the extra oxygen to properly burn the exhaust gases..It will clog up with out that extra air!!!

ftwfred

Dec 28, 2002 | 01:33 PM

heathdaily

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From: kansas

Smog pump questions

>YES!!! You are exactly right!!!Pull the air pump off ANY
>engine with an O2 sensor and yer askin for trouble...
>

Well, maybe not any engine. If a particular engine doesn't put air in ahead of the O2 sensor it shouldn't mess it up to not have it.

>
>the cat also needs the extra oxygen to properly burn the
>exhaust gases..It will clog up with out that extra air!!!

But in that situation the cat would definitely have to go as well.

My 92 F-150 4.9 has had both cats pulled, but I left the air pump and valves intact to the head, the line that ran directly to the cats has been revised, to keep it quiet, and now blows off into the air.

Dec 29, 2002 | 05:46 PM

Farm Dog

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Smog pump questions

I would like to remove the pump from a '81. The cat is already gone and the O2 sensor wire is just dangling. I might need the room to mount up the EFI exhaust manifolds. What might be problems associated with doing this on a '81? whoof