I have modified my P5 engine with MazdaSpeed cams, Injen cold air kit, 4-2-1 exhaust header, Fridenza 7# flywheel and Exedy stage 2 clutch but would like to tune the air/fuel ratios for more power/performance. I have been told by one of the local Mazda tuner that he is unaware of anything on the market. I was hoping that I could use an APEX-I piggy-back air/fuel computer but it did not sound like it was compatible with the P5 ECM. I would like something that has been used successfully. How about some help!

 

go with a wideband and third o2 sensor, along with the apexi afc. it has been used successfully in this application.