So changed my boost control solenoid yesterday to a Mac 3 port as it was bringing on eml and an under boost fault code on my snap on reader . When I changed to the 3 port sensor the eml went out but it still brings up an underboost code the code will delete and stay off for a while but it will come back on if I done a few hard runs up the road in it . I’m wondering do you need a map to suit the 3 port boost solenoid .

 

more than likely as these cars are so sensitive when it comes to that sort of thing

 

Use a oem boost solenoid the mac one needs a remap iirc and you not going to gain anything from it