I have to do emission test this month.
Have a 87 TII all emissions crap removed.
Has anyone tried to pass emmisions with just a high flow cat and no air pump?

 

not happening

maybe if you had alcohol in the tank you could possibly pull it off

 

my brother in VA has a 86 n/a with rb headers, bonez high flow cat and air pump. he blocked off the split air pipe, no air going to the cat.
he still passed emissions no problem.
he didn't add any alcohol or lean out the motor.

 

that's because it doesnt use the split air pipe in an emissions test.

 

huh?????????

 

Try this and post back.

Common belief is that you cannot pass this way. If it works out, then we have all learned something.

Good Luck!

 

i got a fresh motor with about 5k on it. i am gonna lean it out and see what happens. i took the cat from his car and put on mine.
he has passed his car twice with that setup which just baffles me.

 

if you lean it out too much your NOx will go up depending on how the test is performed... and it will only lean out if the engine isn't in closed-loop O2 feedback correction

 

so put in alcohol?

 

I have an 89 TII ALL emissions removed except I have a cat (not sure if it is high flow or not).

Anyways here are the readings from my smog check machine.
HC ~130
CO ~ .6
NoX ~ 200

Note this is not passing for CA specs. It is however very close which tells me my engine is in really good shape.

Not sure what kind of test you are subjected to but if it is an ASM (dyno) test you have a decent chance of passing granted your engine is in good shape and you have a good cat. If it is a no load/idle test you are most likely screwed.


I however have no knowledge of other states emissions specs. If you take your car in for a smog check please post the numbers as I would be very interested.

 

So you didn't have the air pump hooked up right?

 

These are the numbers from my brother's test.
Remember that the air pump is not hooked up to the cat.

 

There is a THING called PORT AIR. See the FSM, Fuel and Emissions section.

The word PORT has a meaning. As in EXHAUST PORT(S).

If you look at the exhaust port on any RX housing, you will see a diffuser just inside the exhaust port. Under that diffuser in each exhaust PORT, is a hole in the housing.

If one were to follow that hole back to it beginning, he would find that hole in the rotor housing leads back to what is called the *spoked checkvalve* inbetween the ACV and the intake manifold.

Air passes thru that spoked checkvalve and goes to the exhaust port. The air originates from the Air Pump.

When at idle airpump air goes to the Port Air. At low speeds and low throttle inputs, air still goes to the Port Air.

With a little more push on the pedal, air will also go to the split air pipe (switching solenoid action {TPS related}). Split air will not be nearly the volumn of the air going to the Port Air though.

When you car is, generally speaking, over 15mph, the engine will go into Closed Loop. As long as the throttle pedal isn't pressed too far (TPS related/switching solenoid related).

Closed Loop means NOW (and not before) the ECU is controlling the AFR to approx 14.7 afr, an ideal air fuel ratio. Helps the catalytic converter......convert the gases to reasonable levels.

Some people delibertly feed all the air to the split air pipe and pass emissions. Whatever floats their boat is ok with me.

There is nothing at all unusual about a car passing emissions tests of 15 and 25mph with no air going to the Split Air Pipe. It's not that big a player at all.

I'm a TRUE BELIEVER in what I just wrote. Cause that's how the cow chews the cabbage. JPG attached is from several yrs ago. Dirty nasty RX-7.

Yer NOx sucks.

 

That is correct. Wasn't even on the car.

WOW!!!! With the limits posted on your brothers car almost every car in the world would pass that test. Unfreakin believable!!! Also it makes no sense what so ever to have a higher acceptable limit at 25mph. Cars make less emissions at 25 than they do at 15. Here in CA the limits at 25 are lower for that reason.

 

Hailers,
I told him he was getting air through the exhaust ports on his car that's why his readings were good. He says no.
On my TII I don't have that.
My question is do you guys think I can pass with just the high flow cat? I am leaning towards putting back the air pump and running a hose straight to the cat.

 

If I get your numbers on my check I should be good. VA and NJ should have the same limits.

 

Don't forget about the visual part of the test. If they do their job and look for the proper emissions control devices you will fail the test.

Also, your brothers test was done on a dynamometer which really helps clean up the emissions especially for Rx7s. If your test is not done on a dyno and they do an idle speed test you will most likely fail.

Good luck with the test make sure you get a free retest in case you fail.

 

Just found out that NJ has the same emission test as CA. So I am in trouble.
I am gonna put the air pump back and run a hose straight to the cat and also put alcohol in the tank and see what happens.

 

yep, only thing i do now is make sure i have port air, and go smog! we even got a car with a really really tired (can't start on its own, barely idles) engine to pass with flying colors. or even on my t2, i passed WITHOUT THE SPLIT AIR PIPE AT ALL

port air works!

 

Looking at the ports, wouldn't headers block those off?

 

the emissions testing in nj actually got alot stricter from wat ive heard. Nj inspection can fail you now for alot of things from worn out engine mounts to headlights not bright enough. Its going to be hard to pass with a 7. The sticker even changed

 

nope. the air pump air comes in around and thru the exhaust sleeve.