Bugger, the report i have is about the pretty really early British isles aw11 ecus which didnt seem to operate a cat more than in britain, so no excess information about exactly what the O2 sensor does below. You will find as a lot of tuning theories as you'll find https://4age20vturboengineforsale81233.blogdeazar.com/26858172/the-best-side-of-blacktop-20v-4age