I am putting on my cats for emissions and I put on my air pump. I noticed there was a hose coming off the second cat and I first thought that this goes to the air pump via an opening that I have right below some vacuum hoses at the back of the engine. Upon ...further thought, I realized that this hose could be the vacuum for the activation of the auxillary ports. And the air pump dumps air into the exhaust manifold... Which one is it. Do I need to get a hose to connect the opening to second cat? Or would it be no good for me. My auxillary ports are wired open anyways. Also for emissions can I just leave the inlet for the air pump open without a filter as I have an aftermarket cold air intake.

1. Do I need to hook up that hose to the second cat for emissions?
2. Will not having a filter on my air pump inlet affect emission?

 

Need to know!! Just about to go to the shop to buy the flange I need and don't want to have to go twice.

 

Well, i found your post a little hard to read, and im not too good with cats/emissions since i dont have cats and most of my emissions is gone, but i think i have the answers.

1. Yes, i believe the output from the airpump goes to the cat like you suspected.
2. It will not make it harder for emissions, but if there is a visual inspection you are not going to pass with your cold air intake. If there isnt, you should have a seperate filter on the air pump because you do not want any debris getting sucked in to there.

 

Today i took my 89 TII in for a new cat at the local muffler shop.
Straight from the muffler shop i went to take emmisions test.
I am running an air pump with no filter on the inlet and a outlet 3/4" hose
reduced to 1/2" at the cat. RB cat back exhaust system, FMIC and SAFC
untuned settings on the afc. hell i don't even if the 02 is wired correctly.

Here are the results

Hydrocarbons
Standards Readings
0.80 1.13 = fail

Carbon Monixide
15.0 2.0 = Pass

Next step i will Change plugs and oil to try and bring the hydrocarbons down.
Any other advice for us guys that still don't know how to pass emmisions?
Do the US and Canada test for the samethings.
Sorry to jump on your band wagon phil.

 

An 87 non turbo car. I've seen one of those before.

The airpump has an outlet hose that goes about a half foot to the ACV.

The ACV sends the airpump air to two places. Mostly it feeds it to the EXAUST PORTS in the rotor housings.

The other place it sends air is to the SPLIT AIR PIPE. An anemic amount compared to the air sent to the exaust ports.

On the back of the series four non turbo intake manifold, there is a large nipple facing AFT. To this nipple is attached a hose that is about six inches long. On the OTHER end of that hose is a pipe called, yes you guessed it, the SPLIT AIR PIPE.

The Split Air Pipe is fairly long. Maybe about three feet long and maybe a half inch in diameter. It terminates at the MAIN catalytic converters small outlet pipe.

Do a search in the free online FSM and you might find a picture. Maybe, maybe not. I know there is a jpg of the split air pipe on this site somewhere.

By the way. Just after the split air pipe mates with the intake manifold, it has a mushrooom shaped checkvalve to keep exaust pressure feeding back into the intake manifold. An just aft of that check valve is a small 1/8 inch tee nipple that feeds air to the AUXILLARY PORT ACTUATORS on your series four engine.

The aux actuators won't work without THAT source of exaust backpressure, unless you make a workaround.

 

Page 4A4 of the series four, 1988 FSM shows the pipe in the FUEL seciton for non turbo engines.

The parts fische for the pipe is page 1-M14, part code 40-375 or something like that.

The FSM can be downloaded for free from the net and the parts fische also.