MOST stg1 is chip/-31, but recommend to do exhaust air filter anyway.
STG2 different injectors light greens,chip/-31 most don't bother.
STG 3 Dark greens(803's)chip/-31
It is recommended on any car even std to do exhaust and air filter, NEED it as a must on modded ones.
A breather is a good idea, above stage 3 it is major mod time ie turbo, a std T3 will run stage three ok but have a hard time.
ESCORT cossie are slightly different depending on whether small turbo(T28) or large turbo(T34).
tabetha