the AI system can switch the air flow from the air pump to either the exaust ports or the air cleaner in response to the O2 concentration in the exhaust manifold.This maintains the air fuel mix ratioof the inlet gas and looks to be controlled by a the thermo switch (TWC), Thermo sensor 1(coolant) , thermo sensor 2(coolant)connected to the emissions computer. The themo sensor on the cat is a safety . So I would do like emsevil and hose clamp it on the pipe if you can.
I just recently purchased a New Magnaflow hi flow cat from 4wheel parts. It it direct fit with flanges and has the place for this sensor. And its Cali legal around 200$
