I'm going to be trying this pretty soon. Give me some opinions, whats more likely to pass?:

Bypass ACV with a host straight to the cat, or the vacuum line on the ACV thing?

I guess I could try both, because if one doesn't work I get a free retest within 30 days, but I'd rather get it on the first try.

I will be posting my results here.

 

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This is a good example of how the stk setup works. Normally the ACV directs the airpump air thru the ACV............then thru the spoked check valve b/t the ACV and the intake............on to the EXHAUST PORTS where it mixes with exhaust gasses..

These EXHAUST PORTS (for those who have not ever taken a RX engine apart) are approx 3/8" holes in the exhaust sleeve which are located approx an inch from the mating surface of the engine housings and the exhaust manifold. This air from the ACV gets mixed with exhaust gasses and THAT mixture moves on down stream ...........past the 02 sensor.........and on to the converters inlet.

I'm not saying the ACV does not pass airpump air to the split air pipe. I am saying that more often than not the air goes to exhaust ports (called PORT AIR in the FSM) and especially this is done at idle speed and low driving speeds.

During the slow and high speed driving check, the 02 sensor is now in the loop and that being the case, the ECU is NOW trying to correct the afr to approx 14.7afr (a lot leaner than a normal idle mixture of ?? 13 to one afr). That's why some cars pass the high speed test and come close to failing the low speed and or idle test (02 in the loop at 25mph). Actually the 02 should come into play at approx 1500-1700 rpm which should cover the low speed test also, but .............not always for several reasons not mentioned here.

If you wan to know when the ACV sends air to the split air pipe, just monitor the signal to the Switching Solenoid and the Relief Solenoids. If Relief stays energized at the same time the Switching Solenoid is energized.........then air is being sent to the split air pipe. IF Switching solenoid is energized and Relief solenoid is NOT energized..........then air is being dumped into the silencer in the right fender on the whole. Ain't a lot of pressure left to send the air to the split air pipe if its being dumped at the same time into the silencer in the fender

Split Air Solenoid adds air when the gear selection is FIFTH or over the top gear. It adds it to the split air pipe. But as mentioned above, that solenoid is NOT responsible for the rest of the times the ACV sends air to the split air pipe (switching solenoid...remember?).

Some of what I wrote is pretty much how the cow chews the cabbage. I do make mistakes especially when typing and watching the tube paying homage to Will Rogers and that other guy who died in the airplane crash (Wiley Post).

 

Hailers, you seem to be very experienced with the ACV system. Ok here my problem... My car failed smog recently because I noticed that the secondary air injection was not working at all. Last night I found out the reason why is because the ACV is not getting vacuum from the hose that plugs into the switching solenoid valve. I found this out by unplugging the vacuum hose that plugs into the switching solenoid, and noticed that at idle, I have air now going into the catalytic converter.

I recently tried running a heater hose straight from the air pump into the cat, and I still failed smog. I noticed that I failed because there was actually TOO MUCH air going into the cat and the converter was glowing red hot and overheating. I passed the 15 mph test with flying colors with 2.43% 02 and then I failed the 25 mph test with 5.28% 02 which is WAY too much oxygen. The problem is that the 02 keeps increasing as the rpms increase.

I guess my question is, what would happen if the vacuum hose for the ACV is unplugged and there is constant air going to the cat? Would the 02 keep increasing as the rpm's increase, or would the excess air be diverted into the relief valve back into the intake, keeping the 02 under control?