Noobs take notice.
If you need an O2 sensor, seriously consider 1 from Vulture Motorsport on here.
Cheaper than the big boys and works a treat.
My economoy went from 15ish L / 100km down to 13,12,11 depending on Anger levels and 10.5 on the Highway.
Highway was 47.95L / 455km=10.54L / 100km and round town 47.30L / 373km=12.68L / 100km <<<--------- From Records.