fastjoon92

Hi. I just got a 1998 lexus sc300 with the 2jz-ge and started to inspect and check some stuff before I started to really drive it. One of the things that is concerning me is that the car is running a bit rich. Is this due to using regular instead of supreme unleaded or is it another issue?

mitsuguy

iTrader: (2)

Why do you believe it is running rich? Grade of fuel will not change it, though I do recommend using Premium - it will prevent the car from knocking however, as well as other potential helpful things (its like $2-$4 more per fill up, just pony up the extra couple dollars, its worth it)

Back to the original, if it is rich, could be an air flow meter or O2 sensor... both would usually set check engine lights...

How do we know it is rich though?

nate579

iTrader: (4)

As long as your check engine light doesn't come I wouldn't worry. It monitors the emissions and as far as its concern its in compliance. Besides Toyota/Lexus are known to run rich until the warm up to operating temperature.