Yes, I've searched. What I didn't find a good answer for was what the effect of cutting the Split Air Bypass wire has. I understand that the solenoid routes air going to cat back to the air box. What I don't know is when power is cut to the solenoid, what state does that leave it in and what is the effect?

I'm an idiot generally, so please be patient. My understanding is that the air pump supplies air to the cat, carrying O2 so excess HCs can be burned in the cat before leaving the exhaust system. If not enough air is getting to the cat, then it won't effectively do it's job and emissions will be high. Does cutting the Split Air Bypass reduce the air going to the cat from the pump? If not, is there a downside to not reducing airflow to the cat under certain conditions?

I need to at least try to pass emissions here in WA. I need the air pump and cat working as well as they can.

I also read that many felt the EGR didn't really do much as far as emissions are concerned. Is this correct? Will cutting the EGR out hurt emissions and if so under what conditions, idle? cruise?

Sorry for the question, but I really did do a lot of searching.

 

If you look at page F-115 of the Mazda 1993 RX-7 Workshop Manual,
it shows a shunt air path around the SAB valve to the cat. I always wondered
how much more air flows to the cat with it opened as compared to closed.
I have passed TX emmisions with the PFC in non-seq mode with a high flow cat and the ACV output going to the cat.

You could remove the actual valve so it flows all the time. I did this later on.
But then, I only ran my cat for the yearly inspection.