Help me!!??
 

So I just got an 04 Mazda rx8 with 44k miles on, when I filled her up I added so fuel treatment into the tank and ran her hard. Yesterday my check engine light came on, so I took it to auto zone and they said cylinder #1 no combustion or something like that. So I chan all 4 sparks plugs and reset the battery and the check engine light cleared. Now this morning the check engine light came on again and the car is shaking, any help

"No combustion or something like" no compression?

I think it no compression I added fuel treatment to it bc I was getting shitty gas mileage and all four spark plugs were messed up so now I'm thinking its coils or something

You need to be sure what the code was.
Was the CEL flashing?
Combustion could mean misfire, which could possibly be bad coils.
No compression, I'm not sure there's a CEL for that, but that means the engine is bad.

Yes the CEL was flashing

Yes likely the coils.
It would be wise to pay more attention to what the MIL or CEL actually is next time.
It will look like this: P0300 - Random misfire detected

Here is a link to all our CELS https://www.rx8club.com/series-i-tec...n-guide-26291/

FYI the RX8 gets shitty gas mileage period. Even when the car isn't running it still gets bad mileage ;)