I understand that if you remove the cat you need to install a resister to fool the ecu but what I wnat to know is wahat size resister and whitch wire(on the downsteam o2 sensor).

 

its extremely difficult to 'fool' the PCM about the cat.... there have only been few stories of success and its not by using a resistor, it was something else.

you'll have to either live with the CEL or get the Cobb AccessPORT that will mask all emmisions CELs

 

What is a cobb acessport

 

read all about it here https://www.rx8club.com/mazdamaniac-183/cobb-accessport-discussion-140117/

 

That looks graet but I'm kinda low budget and a tinkerer. what are the problems assoseated with the risister aprotch.

 

it simply doesnt work...

 

thanks I guess I will have to save or get a highflow cat.