I was Particlewave's tester for the SAI circuit. If the O2 sensor circuit is as effective ,it is a very useful device.
I was not trying to cheat the Smog Laws. I was up against a deadline for the Smog Test and needed the 'sticker'' so I could continue working on fault finding. Without a "Pass" of the Smog Test and the precious sticker, your out of date one makes you CHIP bait.Expensive !
The other problem is the "Drive Cycle". If you research this ,you will see comments that it is a potentially dangerous/impossible procedure in urban areas.
Particlewave's circuit allows a more leisurely approach to solving the SAI issues.
For the O2 sensor circuit, the situation is similar. I had O2 sensor codes despite a newly rebuilt engine and 4 new sensors,coils,plugs etc. I needed to pass Smog to get the sticker, to continue working on a fix. The only hack available is anti-foulers. These are clearly visible and an instant huge penalty in the Visual part of the Test. You do not want to do that ! In my case the O2 code seems to have been aberant but when that comes up on your way to the Test you have no way of knowing it. Just clearing the code resets
all the Readiness Monitors to "Fail" - it is a useless reaction.
The O2 Sensor circuit is easily removable/reversible just like the SAI circuit. It is therefore a great aid to gaining the time to diagnose and fix the problem.
Without the O2 problem-solver circuit , you might mistakenly buy 2 new catalytic converters - a huge and needless expense.
The other caution is that we don't know the long term effect of running with these problem-solvers circuits connected. I expect the SAI circuit would be totally harmless despite the brief unburnt HC. There are adverse comments about cheapo O2 code MIL eliminators(EBay) but Particlewave's test circuit should not be confused with those.
http://www.ebay.com/gds/Truth-about-O2-simulators-/10000000002812356/g.html
I hope this perspective helps others understand the justification for the SAI problem solver circuit and similar devices as a diagnostic tool.
Thanks to Particlewave for helping us.