engine light came on so garage did a check and said it was the cat how ever price was high for a genuine mazda cat so got a cheaper part off the net non genuine after fitting car was great however engine light come back on so took it back to garage who say the light will stay on because its not genuine are they right !!!

 

any aftermarket cat will cause the CEL to go on, eventually if you have a Cobb AP you might be able to bypass the ECU causing it to appear...

A new OEM Cat from the dealer can cost anywhere from $1200-$1500, if your RX8 has less than 80k BY LAW YOU SHOULD GET IT REPLACED FOR FREE, if it's over 80k you can purchase a good used OEM cat with low mileage for less than $500

Good Luck !!!

 

Your laws may vary :/

 

thanks for your info cheers

 

Yea, Silverisk8, you are right for here in the states. But I personally don't know the law in the UK. I would hope it would be the same for the OP sake and the other UK 8 owners.