I say go for it, as well make sure you eliminate the air leaks around the intake and make sure you don't have a lazy caliper on any of the brakes, use an infred temp gun to check to make sure they aren't running too hot.
Originally Posted by Bigjohn88
My e39 528! Burn a lots of gas 14L/100km on city driving, with 200000km do I need to change the O2 sensor? Will I save some gas by replace a new one?