Fox Does a Cat Really Need Air?

[Black1987]

Cats work on a lot more than just heat burning off excess hydrocarbons. They're catalytic converters, meaning they change the chemistry of the gases based on exposure to a catalyst. They oxidize CO into CO2, they oxidize hydrocarbons into CO2 and H2O, and they reduce NOx's into N2.

The air injection inserts oxygen to maximize the oxidation stages of the catalyst, and in some cases, to offset an overall rich mixture. It's there for a reason.

But...do you NEED it? Other than from an equipment-mandate standpoint, I land on "no", because most cats in most circumstances will run a long, healthy and test-passing life without it.

Sooo when you installed your cats, two questions:
1. Did it reduce the smell?
2. How long ago was it exactly and are they still kicking.

Furthermore,
The reason I brought this up, is currently if you go out and buy a catted pipe for our cars (BBK, LMR, or etc) the provision is still there.

Our fleet of cars are in multiple different configurations by now, bumped timing, different HCIs, power adder....soo the answer is not one for all.

However, for discussion purpose lets say HCI bumped timing, gears, no power adder.

I’m thinking getting the magnetically spun cats and just plumbing the air pump straight to the cats due to my current situation.

 

[Mustang5L5]

I'd like to know when exactly the diverter valve lets the air through to the heads and when to the cats.
because I have new heads (FR X307) without the provisions. now I have a setup which directs the air after the bypass-valve directly to the check valve and then to the cats (I took the diverter valve away). But I have also the stock pre-cats and if you're right (the ones who say that the pump is mandatory) then it's only a matter of time when they will fail.

Cold warmup only when the fuel mixture is purposely rich. The air pump directs air into the heads. Once the car goes into closed loop, the diverter sends the air down to the main cats via the smog pump pipe

 

[Mustang5L5]

Sooo when you installed your cats, two questions:
1. Did it reduce the smell?
2. How long ago was it exactly and are they still kicking.

Furthermore,
The reason I brought this up, is currently if you go out and buy a catted pipe for our cars (BBK, LMR, or etc) the provision is still there.

Our fleet of cars are in multiple different configurations by now, bumped timing, different HCIs, power adder....soo the answer is not one for all.

However, for discussion purpose lets say HCI bumped timing, gears, no power adder.

I’m thinking getting the magnetically spun cats and just plumbing the air pump straight to the cats due to my current situation.

Honestly, it's not much work to just keep the pump and set it up to provide air. What's it weight? 5 lbs? Probably robs 1/4HP?

Like I said in a previous post, the basanni X-pipe is just too expensive to assume you don't need the pump. I plan on relocating all the control solenoids to inside the fender and run the plumbing through there.

I have a stock 4-cat H-pipe I ran on my car for a decade or so without the airpump. When I remove it to swap the basanni pipe, i'll be very curious to see if I see the gummed up residue of unburned fuel on the first pair of cats. If it's NOT there, I might be more tempted to ditch the pump.

 

[lizzard]

I have a stock 4-cat H-pipe I ran on my car for a decade or so without the airpump. When I remove it to swap the basanni pipe, i'll be very curious to see if I see the gummed up residue of unburned fuel on the first pair of cats. If it's NOT there, I might be more tempted to ditch the pump.

DO IT! and post some pics

 

[Black1987]

I don’t disagree with you...however my solenoids and valves are gone. All I have is the pump (mentioned in first post)

Been waiting for the stuff to pop up in the junk yard.

 

[MFE92]

The Magnaflow spun metallics DEFINITELY knocked down the stink, and I kicked myself for a long time for running without them so long. I can still smell some HC's but nowhere near as bad as without them.

FWIW, I drive the snot out of this car on road courses. I can't think of a tougher environment for cats. I've had to replace them once, and I wasn't mad, they didn't owe me a thing. This is my second set, and when I got emissions tested this spring, they passed with flying colors. They have 8,000 miles on them, but 2,000 of them are from 24 track events since I installed them. Here's how they tested out on a dyno sniffer test, and how they tested when they were brand new. You can see only minor degradation after hard use and no AIR pump:

Gas.....Allowed....Test now....Test new
HC.......1.00..............0.61..........0.44
CO.....12.00..............1.02..........3.85
NOx.....2.50..............0.87..........0.67

FWIW I set the timing back to 8 degrees for the tests and I make sure the car is good and warm before testing.

 

[NIKwoaC]

Came across this video today, thought it was relevant to the discussion here. If Flowmaster is condoning the installation of their universal cats on a pre-emissions car, then I would guess running them without an air pump is not significantly detrimental to their lifespan.




Also, @MFE92 , thanks for your input. Great information!

 

[Black1987]

Came across this video today, thought it was relevant to the discussion here. If Flowmaster is condoning the installation of their universal cats on a pre-emissions car, then I would guess running them without an air pump is not significantly detrimental to their lifespan.




Also, @MFE92 , thanks for your input. Great information!

Mmm might be worth a try

 

[MFE92]

Christ almighty, is that for a pair?

Oh wait, I see it's for the whole X-pipe.

These are what I have https://www.summitracing.com/parts/mpe-59926

 

[Black1987]

Christ almighty, is that for a pair?

Oh wait, I see it's for the whole X-pipe.

These are what I have https://www.summitracing.com/parts/mpe-59926

Well as the Mustang Gods would have it. i found a new (or barely used) kit for 50% off local.

 

[Mustang5L5]

If you have Visio or access to a Visio compatible software package, I can probably sent you the original Visio drawing.

@jrichker can you send it to my email please?

[email protected]

 

[kendawg73]

I have a X-pipe with 2 cats on it, and it has no provison for air hook up... i think it was a ULP or soemthing... don't remember, get it on the cheap from my cousin, since he sold his car, only has 300 miles on it.. so that's what I"m using when I get my car back together

 

[95BlueStallion]

Last time I tried bathing a cat, it definitely thought it needed air.

 

[CarMichael Angelo]

Last time I tried bathing a cat, it definitely thought it needed air.

Yep, I just confirmed the same thing, put a plastic bag over my cat for 5 minutes, and he just went limp. Removed the plastic bag, pushed on the cat a couple of times...he stood up, and staggered off.

Bottom line: a cat definitely needs air.

 

[General karthief]

I was waiting for the cat jokes to start.
ever brought your own cat to a cat scan?

 

[Chuckman]

what if the cat is in a box? does it need air then?

 

[a91what]

should i take the cat out of the box first if i want to drill air holes in it??

 

[General karthief]

of course, the cat will move around and you'll miss it.

 

[Chuckman]

But will it? It's both dead and alive at the same time you know.