I have a 04 mazda rx8 and my check engine light is on had it hooked up to a computer and it gave a code of p0300 multiple misfires. It starts hard runs like crap and my entire cat glows red. I unhooked the cat to see if it was clogged and nothing changed. Unplugged the sensor (bottom) to see if that was bad but nothing has changed. Runs as if something is clogged, This is my first rotor motor so I have no clue hoping someone can help. 91k 6speed. Thanks

 

Hello.
Hard starts could be bad compression.
Misfires & glowing cat are classic symptoms of bad ignition (coils, plugs ,wires).
Cat is probably bad from the misfires.
If your engine is not already shot, you could start there.
Plenty of info here if you search.

 

Ok thanks like I said I'm new to any of this so just looking for some sort of direction to go forth with this issue. One question tho, why if so would the motor be shot?

 

Read the new owner stickies at the top of the new member section.
Hard starts, especially when hot is a sign of bad compression, which means your engine is dead or dying.
Misfires clog cats.
Clogged cats kill engines.

 

Like I said I'm new to all this, so that's exactly why I asked. These forums rx8 club/discussion are great Google etc etc. But there are so many opinions and few about p0300 code that I needed know where to start, well besides unhooking the cat to see if it was clogged, so thank you for the reply