this is what i heard from a "mazda specialist" :

Hi Sam,

Thanks for contacting us about your RX8. P0410 usually indicates a
sticking solenoid valve and we recommend replacing the valve. The valves
usually actup when they are really cold or really hot. It is not a bad
idea to replace all 3 valves on the intake as the labor is the same and
they all can fail.

I am at home for the night at this time but please give us a call at your
convenience and Charlie Marks or I will get a quote together for you.



Now i have been reading up, posting, and all of that good stuff on this common issue. Some people think because its secondary air injection the valves have nothing to do with it and its 02 sensor issue. Some think simply cleaning the ssv can fix it. DIY is not an option here so does replacing the valves make sense?

 

P0410 can be a multitude of things no way of knowing unless you do some tests.

This is the process I went through to diagnose with just a multimeter and a 12v battery.

It is essential that you perform the below tests in the first 20-30 seconds of a cold start (when the Air pump is supposed to run) not doing so would make the tests invalid. Once the air pump stops you will need to stop the test and wait 6+ hours for car to cool down (maybe even overnight to make sure.

From a cold start (6+ hours since last start, temp below 25 degree) confirm if you can hear the air pump wine (like a vacuum cleaner or go cart sound)

No Sound,
then check air pump fuse
if ok then check air pump relay (search this forum for how)
if ok then check PCM voltages (per secondary air inspection RX8 workshop manual)
if ok then likely need to replace Air Pump.

If there is sound then this means
the Air Pump is ok
the Air pump fuse is ok and
the Air pump relay is ok

This leaves the problem to either
the Secondary Air Check valve or the Secondary Air Injection Solenoid OR vacuum line leak or Blockage to exhaust manifold

To check the Secondary Air Check valve
Start the engine cold ensure the air pump is running then unplug the thin vacuum line connected to the Check valve then put your finger on the hole (of the check valve)

If there is no vacuum (suction) then the Check valve is blocked - replace
If there is vacuum - then the Check valve is good move to next


Put your finger on the vacuum line hose (the line you unplugged from previous step)

If there is no vacuum on this black hose then the either there is
a leak in your vacuum line (check for loose connections or cracks or breakages especially the 90 degree bends) Or
the solenoid is dead - replace (search this forum for how to remove and test)

If there is vacuum this means - Secondary air solenoid is good

By going through the above means you have eliminated the Fuse, Relay, Air pump, solenoid, check valve and vacuum hoses as the cause for P0410.

Leaving the last thing:
Check for blockage from check valve to exhaust manifold - Carbon build up is common

If going through the above does not diagnose your issue then you may have a PCM problem, faulty O2 sensor or maybe a blocked cat.

Hope that helps

To reiterate the P04010 can be caused by any one of the above parts so don't take a mechanics word / guess. Proper diagnosis can point you to the actual cause rather just replacing everything and hoping for the best.

 

Best solution, RB block of plate and a COBB!