I want to know the truth. Why would you need the smog pump to pass emissions when the only time it is actually helping with emissions is when the engine is cold, is this true? By the time you drive to the test sight, your motor should be nice and warm, correct? So unless you have visual inspection, why not get ride of the eyesoar in the engine bay. And to be on the safeside, can't you just add some rubbing alcohol (or other fluid) to 1/4 tank gas and then go to the test sight? What are some of the cheats? Don't tell me "I heard this......" I only wanna hear "I did this and I passed". Same with the cat converter. I've heard people that have gutted it and passed. Is this true? And when you gut it should you put a straight pipe through it so not to introduce turbulace into the exhaust system? Come on guys, lets get the truth out there and put some of the myths to bed. I really only want to hear some 1st person experiences. This is for everbodys benifit.

 

The job of the cat is to combine any CO and unburned HCs with oxygen.

It cannot do this unless there's some oxygen in the exhaust stream. Some way, there has to be some. Either the engine has to be set up too lean; or the AIR pump has to be there. The cat can't just miracle up oxygen out of nothing.

The AIR system is always active. What changes when the ECM enters closed loop, is that it goes from putting the fresh air into the manifolds, to putting it into the back half of the cat. It does not cease to be active when the engine warms up, as your post would appear to imply.

What's a bigger eyesore; some part under your hood (which if you know how to work on cars, stays closed for months at a time, so you never even see it); or a car that doesn't pass inspection, so it sits on blocks in your front yard?

IMO this "clean up the engine bay" business is a VERY BAD IDEA. A surprising number of people who hack up their cars for that reason, end up merely devaluing them and rendering them unusable. It ranks among the very poorest of reasons for hacking on a car.

Rubbing alcohol is almost totally ineffective at altering emissions readings. Especially if you put in one little pint bottle. Denatured alcohol, on the other hand, might have an effect, if used in sufficient quantity; like, a gallon mixed with a quarter tank of gas.

The only way to pass with a gutted cat, is if they don't sniff your car; or unless Mr Green is sufficiently present.

 

I just etested mine. Runs good, cat is good, has a bad valve seal leak, no ses lights, 2 qts of alchohol in a 1/4 tank, car hot, Failed.........heres why. I run my timing a little more advanced than stock. I had mine at 8* advanced and stock is 6*. I figured I should back it down and toss in a new 02 as mine is probably oil poisonedbut I couldn't get off of my lazy ***! So I reset the timing a 0*, installed a new gm 02 and BAM! Origional readings passed on everything (barely) except the idle portion where it blew way over. The second test EVERYTHING dropped by ALMOST HALF and the car flew through the test! Now keep in mind, I have removed the air pump and have NOT cap'd the convertor air tube and I also have no egr function as I have no vss signal to the computer which causes your egr,canister purge and high speed lean-out not to function in these TPI motors. Am I telling you to remove your air pump....No.....I removed mine for appearance and weight savings. If you have a visual you will fail.

 

not including the visual part, can a car pass emissions with out an air pump, cat & EGR? yes.

everything has to be in good condition, motor, ignition, & computer system.
my car has passed tail pipe emissions the last 2 times with empty cats & a non-working EGR.
i do have the AIR pump & it works mostly as designed, i never got around to hooking it up to the cats, but then with the self cleaning cats i have, it doesn't make any difference when warm.
my motor is dead stock. on the last test i had around 60~70000 miles on the ignition parts, spark plugs included & was over due on the oil change.

i have done some chip tuning, & i do have full access to to a 5 gas analyzer & the state certified emissions machine which i used in tuning the chip.
i didn't pass with flying colors on HC. a pass is a pass & thats all that counts.
i will do an oil change & put in a new set of plugs just before the next test, i may have to replace the cats if i fail the first time.
NOx should be lower now that my EGR works.

my numbers on the last test were,

low speed.... standard ,..... actual
HC ,............... 144 ,............. 144
CO ,............... 0.92 ,............ 0.65
NOx ,............. 1014 ,........... 540

high speed... standard ,.... actual
HC ,............... 148 ,............. 147
CO ,............... 0.83 ,............ 0.62
NOx ,............. 1110 ,........... 717

 

Smog pump finction, in a nutshell:

Cold engine (open loop): blows the air into the manifolds
Warm engine (closed loop): blows the air into the cat
Decel from high RPMs with throttle closed: blows the air out the silencer to open air to prevent exhaust backfire.

 

Come on guys/girls, 83 of you have read this, but only 4 replies, feel free to put your in. It's for everybodies benefit, not just mine.

 

I've always thought smog pumps to be the best GREEN joke. C'mon, lets inject some fresh air into the exaust stream to make the emissions cleaner. Lets see, outside air into headers or whatever than back out into fresh air at the cost of power. I still run a cat and it works without the air pump.

 

I pulled the AIR belt to do a before and after on the sniffer: No difference... well, close enough. HC was higher with AIR on.

 

as sofakingdom said, the cat does need fresh air to function at it's best.

the newer factory cats do work better than the older factory cats did when they were new.
fresh air injected into the manifolds does help clean up tail pipe emissions by allowing the mixture to continue to burn in the manifolds & it helps in getting the cats to light off sooner.

the AIR pump robs very little power from the motor. enough that you can feel it? probably not.
enough that you can see it at the track? probably, if you & your car turn very consistent times.
for the average weekend warrior, probably not.

you can get a bigger power gain by doing away with your clutch or flex fan if you have one & going to an electric fan, or going to an under drive pulley set.

if your AIR system is all in good condition & you just remove the air pump & leave the rest of the system intact with the air pump hose left open, the AIR system will still reduce emissions by a small amount.

running the emissions test with the motor turning as close to the max RPM as allowed by your state as you can normally will drop HC, CO, & NOx. i know this by testing a few auto trans cars with them first in drive & then ran the test a second time but i held them in a lower gear.
to verify the results, after letting them cool down for a few minutes i re-ran the test, but reversed the pattern, first holding them in a lower gear & then doing the second test in drive. the readings were almost the same on each test for each car i tried this on, almost every time higher RPM reduced all 3 gases. i did this on about 20 cars with only 1 or 2 cars showing little to no change & 1 showing an increase in emissions with higher RPM.