Help...air tube to cats necessary? I stink of fumes...

[Fastime331]

I am finally going to do something about these fumes. My wife will not drive the car because she says I stink of fumes when ever I get out of the car.

I currently have BBK 1 3/4" LONGTUBE headers, offroad H-pipe (no cats) & full exhaust w/tips.

I'm going to buy the BBK-1662 shorty x-pipe with cats. My question is,

do I need the air tube from the air pump or not?

Will the cat's burn up if I don't?

 

[90mustangGT]

So let me get this straight, your afraid of burning up the cats, but you don't have cats???

If your running that exaust setup, delete the smog pump assembly.

 

[Matt90GT]

The air pump has nothing to do with the cats. It is there to dilute the emissions by pumping "fresh" air into the exhaust.

 

[Mustang5L5]

I'm going to buy the BBK-1662 shorty x-pipe with cats. My question is,

do I need the air tube from the air pump or not?

Will the cat's burn up if I don't?

I've been running a stock H-pipe with cats for 2 years with no problems.

 

[Fastime331]

The air pump has nothing to do with the cats. It is there to dilute the emissions by pumping "fresh" air into the exhaust.

I just thought that the fresh air might just be a method of providing the cats with an external source ambient air to assist with the chemical conversion that takes place.

Just making sure I don't ruin a $400.00 x-pipe

 

[blk92stangg]

I thought the air tube was to supply enough O2 so the cats can burn off the extra fuel in the exhaust. Although the tube runs downstream of the first set of cats, so, hmm, not sure after all. I don't see how pumping fresh air into the exhaust without cats can "freshen" anything up either tho. I think the manufacturers just put it there so people changing to an off road pipe don't need to delete the smog pump.

 

[jrichker]

The air pump has nothing to do with the cats. It is there to dilute the emissions by pumping "fresh" air into the exhaust.

I don't think so...

According to Ford Fuel Injection & Electronic Engine Control 1988-1993 by Charles Probst, the extra air is to help the catalytic converters burn off the unburned hydrocarbons. It is a reaction between the unburned hydrocarbons and the excess air made possible by the catalytic converters. The resulting catalytic reaction converts the hydrocarbons into water & CO2.

Later converters were designed with a different combination of catalysts and don't need the air (or smog pump) injection pump.

I am finally going to do something about these fumes. My wife will not drive the car because she says I stink of fumes when ever I get out of the car.

I currently have BBK 1 3/4" LONGTUBE headers, offroad H-pipe (no cats) & full exhaust w/tips.

I'm going to buy the BBK-1662 shorty x-pipe with cats. My question is, do I need the air tube from the air pump or not? Will the cat's burn up if I don't?

The cats ultimate lifetime will be shortened without the air pump. Not having the air pump will not cause them to burn up, it will cause the catalyst to coat over with carbon and sludge. They were designed to use the excess air to promote the burning of the leftover hydrocarbons. This controled burning process helps keep the catalyst clean and efficient.

 

[Michael Yount]

As usual - Jrichker nailed it (others in the thread too). Air pump works with the cats to provide the excess oxygen necessary to help further oxidize harmful emissions into harmless CO2 and H2O. Many people run without it, but cat life and effectiveness are reduced.