Originally Posted by HAILERS

Too rich a fuel mixture reaching the catalytic converter dooms it to a short life span i.e. clogging.

The purpose of the ACV is to.........prevent too rich a fuel mixture reaching the converter by mixing fresh air in the EXHAUST PORTS prior to the converter.

A common mixute coming out of a RX at idle is in the 13afr range i.e. a rich mixture. That is with no mixing of airpump air with it. Once the airpump is working, that afr is in the range of 15-16afr.

The airpump air is not injected in the exhaust ports when driving at a cruise speed, because the engine is in closed loop mode for the 02 sensor resulting in a 14.7 afr range.

Step on the pedal at cruise and the *switching* action is taken within the ACV and air is injected in the exaust ports again. There's several variations with the switching action in in the ACV.

Ever notice WHERE the air tube is on that converter? Take a look in case you forgot. Ain't prior to the exhaust air entering the catalytic converter. Here's hoping you did'nt spend more than a C note on that converter and are'nt going to leave it on the car for more than the time it takes to get inspected.

Think about this just for a half second or so. Your being told that MAZDA eng were such block heads, that they didn't realize that all they had to do was run a straight tube from the airpump to the catalytci converter.

So? What was it. They had brothers in law that made ACV and they thought they'd just throw some business their way? Or had stock in the big ACV company? Yeah. A consiracy.