2004 mazda rx8 with 68k on it. Purchased it about 7 months ago, I recieve 300kms to the tank, with 20%highway/80%City Driving. Purchased Platinum Iridium spark plugs by NGK, as well as coils and wires from NGK. Had my mechanic put them into my car ( did not watch him do it ). He Then informed me that there was also a Vacuum Leak? something about the platinum on my After Market cold air intake. When driving it home, I decided to see if it would still missfire, when driving home I red lined it at about 120kms per hour, when it began to missfire. Missfire consisted of CEL flashing repeatedly, drove it home. Parked in the driveway, checked the car, no smoke (only 10 minute drive).

That was as about detailed as i could get into this. I Need Help!!

 

are the coils oem coils? Is everything connected properly? What intake do you have?

 

Coils are NGK, and cold air intake is AEM. to be honest im not sure if its connected properly, im not too bright when it comes to cars.