From my readings here I understand that if you remove the air pump you should also remove the cat, or replace it with a high flow cat. Is that correct? If so, how long (hours of operation? miles?) would it take before it becomes an issue with the stock cat in place?

I'd like to remove the air pump while my front clip and core support are off which makes things a lot easier to work on. However a new exhaust system isn't in the cards quite yet, although it is desperately needed. Can anybody provide a pointer or suggestion as to what brand or style of high flow cat is recommended? Thanks.

 

Is there any reason you want to remove the air pump? It does not take much power to run, and it can only help emissions. Any 3-way catalytic converter is going to need fresh air supply for the oxidation part of the reaction, so if you're going to bother to replace the cat, you should also keep the air pump.

As for how long you can run without the air pump, it's hard to say. It will depend on how well your engine runs, and how much unburned gas it puts out the exhaust. Part of the air injection system strategy is to pump air into the exhaust manifolds to start the reaction there during warm-ups, so less fuel ends up downstream, where the cats don't work very well when cold. So if your engine is well tuned and you don't do a lot of cold starts, it can last longer than if your engine is running poorly and you only run for short durations when cold.

 

The desire is to avoid, what I am led to believe, is the inevitable ceasing of the air pump along with shredded belt and attendant sitting by the side of the road waiting for somebody to tow me home. That, coupled with removing a bunch of plumbing so I can actually work on the engine makes it attractive.

The desire is to have the engine running cleanly and properly. Obviously it won't be "like new" but I'll do the maintenance needed to get it running cleanly. Unfortunately due to the nature of where I live, there will be a lot of cold starts without much long running. I live on a island. The max speed limit is 40. It's only 7 miles to town. My work van averages only about 6,000 miles per year and the truck will probably only average 4-5,000 miles per year max.

 

We all know what the air pump does, just like all the guys with the 6.0 that delete the EGR, I have removed many air pumps threw the years and dont recall having to replace the cat. I took off the air pump, brackets, diverter valves, hoses, belts and cut the air tubes an inch above the manifolds heated with a torch and hammered them over to seal the exhaust. Never had a problem, keep the truck running good and you wont have a problem.

 

I understand the clutter of the air plumbing; I have to remove them whenever I change the spark plugs on my Mustang. But I have to keep them where I live due to the biannual smog inspection.

My experience with the pumps is that they jam up with disuse; I took off a couple before, and it seems like after sitting for just a couple of moths they start to get stiff to turn, and leaving them for a year, they totally jam up. But I guess I'm lucky that I've never had one jam up during operation. My Mustang is more than 27 years old now, but I don't live in a cold climate anymore.

 

David, Thankfully this is a 351W so I don't have that headache to deal with. I appreciate the info.


xlt4wd90, no emission checking to worry about here. I'd like to keep the cat to get rid of unburned hydrocarbons, but would love to rid myself of the extraneous junk tacked onto the systems.


The truck sat unused for several years before I bought it and has only been driven about 5 miles total since then, so who knows. But I don't trust it to not let me down. Especially since if I take it the mainland it'll cost a boat load of money to get it back home if it fails.