im a newbie

hi im new to the subaru club but would like to say hi ....im from the uk i have a 1994 import subaru impreza turbo black with gold wheels and love it ...car has a fault just developed we think its a 02 sensor as it drops and gains revs on tick over once it has warmed up and then white condensation from exhaust.. have cleaned and changed maf no diffrence there ......
i will be asking questions here if i can not solve .......