Hello all.

I just purchased a used 2006 Mazda RX-8 (1.3L Automatic) with 155xxx miles on it as my first car. Though it has some cosmetic damage, the car seems to drive great and there were no immediately noticeable problems with the engine. However, seeing as this is my first car purchase and my limited knowledge about the model, I wanted to see if anyone had a particular list of components I should look at to ensure quality. As it is now, the car doesn't pass inspection and the OBD codes indicate some kind of issue with a catalyst inefficiency. Any ideas as to this issue or a general first-time owner's guide would be much appreciated, as well as anyone that may have some pointers on some first basic aftermarket mods I might want to pursue. Thanks!

J.