i have a tuned v2 sti and wondered if anyone knows if its safe to put a cat on it to put it through an mot. im not sure if it will upset the ecu which is an APEXi. Any help please

 

It will be mapped without the cat, but it would be ok to drive off boost to mot then back and swap over again..

 

The cat will need to be very hot to work at its best. So unless you are driving for a few hours before, driving off boost won't get it hot enough. Its more likely to kill the cat itself, overtime not instantly, then damage anything else.
If the cat has been sitting for a while, then its best to use it for a week or so prior to the MOT.

 

thanks guys, not too bothered about damaging the cat. more concerned about engine