Can anyone help ? I have a apexi air flow converter in my classic sti ive not had the car long i know i sound thick but what does it do ?It ranges from -0 to 21% its set on 3 at the moment if i mess about with it can it blow my engine up?

 

yes you can , scooby clinic advised me to remove mine as kev said he'd seen to many knackard engines due to them being mis set up,, sell it and put money towards a remap