The carbon should come off real easy.I'm on my second dizzy cap cause I was taking too much off those 4 points..the metal comes off quite easy too..
I use a flat head screw driver and chip /scrape it off,it takes 45 seconds for each one,anymore and more than likely you are taking the metal off.It's just easy to do..
The 02 sensor is easy to install,just gotta make sure it's installed on the 1 pipe on the headers i.e. where the 4 meets the 2 then meets the 1,there,that way the reading will be correct as it will be reading all 4 cylinders.If it isn't there it should be moved there,if a bung isn't already there it can be made easily and the other bung plug up with a short bolt,so it dosen't stick through into the pipe.The 02 sensor wire will need to be extended.
Also make sure U are ordering the correct 02 sensor,can order a bosch one from global spares or the likes.
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