ok, so lets assume the AFM circuit on a n/a s5 is perfectly fine, both wiring and afm. is there ANYTHING else that could possibly cause an afm code? does anybody know where to find out exactly what circumstances have to be met in order to throw a trouble code?

 

You car will run horrible with a bad AFM. Is this what you are experiencing? The ECU in the RX7's is pretty easy to understand when it comes to trouble codes and I find it accurate enough in what it tell you. If it finds something specifically wrong, then it usually ends up being what it says (unless you have multiple codes, then thats a case where one malfunction could be triggering other codes).

Per the FSM, Code 08: AFM:
Malfunction Cause: broken wire, short circuit.
Fail safe function: basic fuel injection amount & ignition timing fixed.

 

it actually runs pretty good. when i first start it it runs somewhat poorly when cold, but when it warms up it idles nearly as well as it should, except for it only idles well at around 1k rpm instead of 700. i've already played with the idle control screw, but 1000 is where it wants to idle.

i've checked all the wiring, it's fine, and the maf resistance read fine, but i even replaced it anyway to be sure. made no difference. i've gone through the fsm like a million times. and if i did have any other codes i won't know about them till i fix this one cause it's the lowest number code. is there a way to read multiple codes on these cars?

i was really hoping there would be some sort of guide that tells you exactly what conditions set off codes somewhere.

 

Check your TPS and adjust it according to the FSM. Search here for more info. That is odd the AFM is throwing a code, reset it by disconnecting the battery for 30 seconds after you adjust your tps and see if it comes back.