prep2

I have a 94' LS400 with 123k miles and up until a month ago it's been getting about 18-20 mpg. Now it's getting 13-15mpg. I've searched the forum for answers. I've read about the temp gauge, spark plugs, and O2 sensors being the problem. I do not have a check engine light on so O2 sensors should be fine. I think the temp gauge is fine because (correct me if I'm wrong) rpm drops to 600 when it's warm. My tires are pumped to 31 lbs. Spark plugs ?????not sure how to check??? Any suggestions???

e-man

I could be wrong, but I seem to recall reading about a month ago someone who had this exact problem with an LS. I'll try to find it with a search . . .

Here is the thread I was thinking of:

https://www.clublexus.com/forums/sho...ad+gas+mileage