Hi All,
Could do with a bit of advice regarding changing my O2 sensor. When i first got my car it was a J spec TT auto, and used to return about 28 - 29 mpg, that was 7 years ago mind. Since then i have converted it to manual with a V160, and have a Super Dragger, 2nd decat and performance air filter. I tested it over a 1000 miles recently and am now getting only 23.5 mpg.
Having read a lot on here about how O2 sensors are service items, and with my MOT coming up i thought i'd bite the bullet and buy a new one.
I just back from my MOT man, and the emmisions test was passed with flying colours. The readings on the fast idle test were, 0.119% for CO, 26 for HC, 1.010 for Lambda and the natural idle CO was 0.125%.
I am now wondering if i need to fit the new sensor as all the above tests were done with the old one in. The engine runs pretty sweet, however occaisionally it does tick over fast even when warm, and the revs dont drop very quickly between gear changes. Can anyone tell me whether i would benefit from changing it, or what could be causing the reduced mpg. The 23.5mpg was done on only normal driving with the occaisional blast, i can only imagine what i would get if i thrashed it all the time.