Which is better

Removing the smog pump from a car with OEM catalytic converters will eventually cause them to clog and fail.

Removing the pollution control equipment from a 5.0 Mustang is a bad idea. All you have accomplished is to make the computer mad and spit codes. The pollution control equipment all shuts off at wide open throttle, so the HP losses from it on the car are 2-5 HP. The catalytic converters may soak a few more HP than that. None of the pollution control equipment reduces the HP enough to cost you a race in anything but professional drag strip competition. I seriously doubt that you will be in the final runoff on “Pinks”, so leave the smog equipment in place and make sure it is working correctly.

What happens when there is no extra air from the smog pump...
As engines age, the quality of tune decreases and wear causes them to burn oil. We have all seem cars that go down the road puffing blue or black smoke from the tailpipe. Oil consumption and poor tune increase the amount of HC the oxidation catalyst has to deal with. The excess HC that the converters cannot oxidize due to lack of extra air becomes a crusty coating inside the honeycomb structure. This effectively reduces the size of the honeycomb passageways and builds up thicker over time and mileage. Continuous usage under such conditions will cause the converter to fail and clog. The extra air provided by the Thermactor Air System (smog pump) is essential for the oxidation process. It oxidizes the added HC from oil consumption and poor tune and keeps the HC levels within acceptable limits.
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Newer catalytic converters do not use the Thermactor Air System (smog pump) because they are designed to work with an improved computer system that runs leaner and cleaner
They add an extra set of O2 sensors after the catalytic converters to monitor the oxygen and HC levels. Using this additional information, the improved computer system monitors the health and efficiency of the catalytic converters. If the computer cannot compensate for the added load of emissions due to wear and poor tune, the catalytic converters will eventually fail and clog. The periodic checks (smog inspections) are supposed to help owners keep track of problems and get them repaired. Use them on an 86-95 Mustang and you will slowly kill them with the pollutants that they are not designed to deal with.

trebor3170 said:

Well ,......… Commiefornia is prolly a lot closer to Nazi Germany, than Florida. But honestly, I don't understand why peeps are in such a big rush to delete the emissions, especially in states that require testing, since it has been proven time and again, that the deletion does not really improve performance that much

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For me, it really comes down to engine bay appearance. I started out in high school with 60’s stangs, and moved on to foxbody’s. I am old school through and through, and the more I can clear out of my bay, the better.

I'm kind of doing the same thing. I've taken the smog pump and extra hoses off my 66 289 California car. It has factory AC and power steering, but now there's no pulley for the AC, it won't go straight from the crank pulley to the AC unit (it runs into the water pump pulley that has only two grooves). Any suggestions? I want to keep AC and get it working. FYI, I took smog pump off for cosmetic reasons, but safely packed it away just in case. Is there such thing as a 3 belt water pump pulley that would take a belt from the crank (front pulley now not in use after smog pump removal) to the water pump to the AC unit? Thanks in advance.

Angelnava81 said:

I’m deleting the smog pump and eventually the a/c I’m wondering what is the better route getting a shorter belt or the free spinning aluminum pulleys also any tips and advice would be greatly appreciated

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Here ya go....1990 Mustang GT 5.0 302.No AC,no power steering, no smog junk Pulley here https://www.ebay.com/i/290580284103...sZ2XdRNVo3leYzH29k0d3twQS1TabAQgaAqhYEALw_wcB

Some cars do not have the option delete an accessory and go to a short belt. This is where dummy pulleys were originally meant for.

In the case for smog pump on 302's luckily the shorter belt is an option. The ONLY minor advantage of the dummy pulley is a new belt is not required.

Shorter belt!

Mustang5L5 said:

Another reason they don't enforce it is because cars rot out in 10-15 years here due to the salt. Not a whole lot of pre-2000 cars on the road here.

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Kinda like here in NJ
NJ dumped all testing of cars 1995 and older. (basically older than ODBII)
Why? Because it costs too much and nobody is driving cars that old daily.
The tree huggers were pissed. But the reality was at the time, out of millions of cars registered here, only a small percentage were that old.
And of those, thousands a month were never being registered, driven again or are junked.
The problem really resolved itself.

With that said, i'm a fan of running cats these days (i was not in the past).
Oddly enough my dohc 4.6 passed 1990 standards at inspection without them. That's how much better new tech is.

Just don't think it's possible for cops to know and understand the emissions devices on a 100,000 different models of cars and i seriously doubt anyone gets harassed without at least giving them some reason to get on your case.