Emissions parts, what can I remove?

[91longroof]

So after doing the valve cover gaskets this past weekend, I realized that there is a bunch of crap under the hood of this beast. I read elsewhere on here that I can safely remove the air pump junk with no issues, so what else? I don't want to affect the mileage or driveability, but if things can be removed, I'd like to. We don't have emissions testing here, so that won't be a factor.

[mcninetyone]

You can remove the cats, and that will make it even easier to remove the air pump crap. Since it feeds directly into
your "Y" pipe on both sides.

[sly]

if you're in an emissions controlled area... keep the cats. If they don't do visual checks, you can remove the smog pump (directly under the AC compressor) and all the hoses/vacuum lines attached to said POS. Plug up or weld the side pipes from the cats when you remove the air injection pipes. You can also remove the crossover pipe on the back of the engine, but you'll need to plug the holes with something. Most people that do this cut some 1/4 inch plate steel and drill it to make a hole for the bolt and then ultra-copper RTV on it for good measure to seal up the air injection holes in the back of the heads. others just get some pipe caps and cap off the pipe where the check valve is on it.

Definitely check the emissions requirements in your area first. Some areas are ultra anal about having all the stock crap on it... others, don't care as long as it passes the sniffer test. If you're not in an emissions controlled area... take out the cats too for a little more get up and go. Just a little though.

[MadRunnerMax]

Thanks for asking this 1 for me and thanks for the answers.

[TomO]

So, from what I understand, you can keep the cats on the car without running the smog pump? I thought I read somewhere that the cats need the extra air from the smog pump to keep from getting fouled. But that's probably wrong.

[1990LTD]

So, from what I understand, you can keep the cats on the car without running the smog pump? I thought I read somewhere that the cats need the extra air from the smog pump to keep from getting fouled. But that's probably wrong.

you're correct...there is piping in place to send the air down to the cats which will leak if not sealed somewhere.


the air aids in combustion in the catalyst but i do not believe it's required. i see the logic behind the thought though

[87_crown_vic]

i usually remove the smog pump, along with piping and a/c in my cars to free up space under the hood... the pipe on back of cylinder heads when removed can have the ends cut and remount the ends on opposite sides to block of the holes in back of cylinder heads.. here is a pic of the stuff mostly removed from passenger side of engine...

[88Vic]

Is there a belt that fits when you remove just the smog pump? Also I imagine removing the pump won't affect the belt routing, but sometimes it does which is why there are dummy pulleys for doing a/c deletes and whatnot.

[mrltd]

Is there a belt that fits when you remove just the smog pump? Also I imagine removing the pump won't affect the belt routing, but sometimes it does which is why there are dummy pulleys for doing a/c deletes and whatnot.

Yes, there is. Not sure off the top of my head, but it's been discussed ad nauseum. A quick search should be able to find it.

[1987cp]

Everyone always says 56" for 302s, and I think that's what I have also. I recall buying a 60" when I wanted an A/C-only belt for a 351. Wrap a piece of string around your pulleys and put it on your parts store's belt-measurey device, and beg for permission to test-fit the belt in the parking lot before you pay.


OP: What you can *get away with* depends entirely on how things are enforced locally. johnunit in Kanadia claims cops there will pull you over and ask to look under your hood and write you up for anything that looks like a "performance" piece. NW Indiana there's a visual check for cats and a sniffer test just to be allowed to register your car, but it's apparently not super-strict about EGRs and smog pumps being present since I know of a sniffer test being run even after the test-center people were flipping out over an open air cleaner. Michigan and the rest of Indiana, it appears no one ever checks anything emissions-related for any reason, which is the way it should be.

FWIW, the EGR system can supposedly have an effect on fuel economy at very low speeds, so you might consider keeping it even if everything else goes byebye.

[TomO]

I'm still somewhat confused about the cats. My understanding is that these cars are programmed to run slightly rich and that this slightly rich mixture will nearly fully combust with the aid of the extra air supplied by the smog pump, and that this combustion occurs in the cats for the purpose of "super-heating" them, which in turn, is for the purpose of "burning" some of the harmful exhaust emissions.

The part that confuses me is that I'm thinking this rich mixture -- if it does not combust -- will cause carbon build-up in the cats. And, if you don't supply the needed combustion air by disabling the smog pump, then you won't get full combustion of the rich mixture in the exhaust.

Sorry to belabor the point, but either I missed any previous explanation of this or, I need a simpler explanation in order to understand why the cats won't get fouled with carbon by disabling the smog pump (maybe my assumption above is incorrect).