NEVER randomly replace parts without first checking to see if they are actually failed.
Check the Monitors and see what emission systems are not in state of readiness this can be a clue to where to look for your problems.
While you did not get a DTC indicating a failing CAT it also may be a consideration to look into.
As well you may have a ECU problem.
But i would recommend NOT to replace any more parts. This often time as you have found does not correct the problem and can add to more problem from the original.
My advice and don't take this personal you do not have the experience and know how to properly diagnose your problem. You do have apparently good DIY in replacing parts so I would get a service shop that has at least a certified ASE Technician to tell you what your problem is and then you can correct it. Otherwise, DIY on forums will likely give you more advise to change more unconfirmed parts. In other words, they will be "guessing"!
BTW you car passed the CA emission testing and was giving the registration for CA. It is NOT "RIGGED" for CA. The CA compliances is stricter than the other states but your year still would have passed the CA requirements and I sincerely doubt any part was added to make is CA compliant. When CA changed the requirements for testing your year was only required to OBDII test not tail pipe. Never the less your Mazda also does not get any allowance in the monitors and all must be in state of readiness. All this was at least from what I recall when I test for my testing certification 2 years ago. I am NOT any longer CA emission certified mainly because I don't work in a shop that offers the CA emission Testing any longer.
Check the Monitors and see what emission systems are not in state of readiness this can be a clue to where to look for your problems.
While you did not get a DTC indicating a failing CAT it also may be a consideration to look into.
As well you may have a ECU problem.
But i would recommend NOT to replace any more parts. This often time as you have found does not correct the problem and can add to more problem from the original.
My advice and don't take this personal you do not have the experience and know how to properly diagnose your problem. You do have apparently good DIY in replacing parts so I would get a service shop that has at least a certified ASE Technician to tell you what your problem is and then you can correct it. Otherwise, DIY on forums will likely give you more advise to change more unconfirmed parts. In other words, they will be "guessing"!
BTW you car passed the CA emission testing and was giving the registration for CA. It is NOT "RIGGED" for CA. The CA compliances is stricter than the other states but your year still would have passed the CA requirements and I sincerely doubt any part was added to make is CA compliant. When CA changed the requirements for testing your year was only required to OBDII test not tail pipe. Never the less your Mazda also does not get any allowance in the monitors and all must be in state of readiness. All this was at least from what I recall when I test for my testing certification 2 years ago. I am NOT any longer CA emission certified mainly because I don't work in a shop that offers the CA emission Testing any longer.