A friend had this happen after installing a S2 gearbox into his S1. He didn't secure the neutral/reverse wires well enough and they melted on the exhaust and shorted out.

Mine blew, too, but I never figured out why. It's possible that I have a similar issue to my friend because I just noticed that my reverse lights aren't working.

I was trying to leave a McDonald's parking lot when mine died. Had to swap the fog light fuse in its place to get running again.

 

which one is the PCM relay?

 

So i have two rx8 one a 04 automatic and one a 07 manual and i had the 04 sitting in the garage for about 2 weeks and when i went to fire it up it wouldn't start but the atleast it would actually attempt to start but ive fixed that one but now my 07 was running just fine until one day it lost all of its power barely starts and barely idles so i looked under the car and the cat was all red so i put it in the garage and jacked it up to work on the exhaust and the clutch. The first thing i did was took the battery terminals off the battery and then took the cat off and busted it up and since i was waiting on the clutch to get in i decided to put the cat back in and fire it up to see if that fixed the issue of starting and idling. When i went to fire it up the battery was dead so i charged it and when it was fully charged i tried to start it and it wouldn't start. All it sounds like is air rushing out of the exhaust there doesn't seem to be any spark and then exhaust smells just like fuel. Was wondering if its just cause the car sat for a week cause the other one also had an issue starting after 2 weeks. Or if it was because of busting all the stuff out of the exhaust. I'll post all the codes that it had before i took the exhaust out