Rehzy

Hello, This is my first ever post on this forum and I'm having an issue where my fuel range decreases by 2. I bought the car at 80k on May 2022 and now its at 85k August 2022. This issue is really annoying, I'm always at the gas station getting gas. I'm looking to replace my spark plugs and maybe fuel injectors to see if that helps. If anyone had this issue before please let me know. I recently had a p0430 fault code, there was a pipe leak and it got fixed. Now the code is gone but Im still getting poor mileage.
I would fill the gas to a half/quarter half tank because whenever I fill the gas all the way up the fuel range decreases by 2 so theres no point in doing that which is why I need to fix this issue ASAP! thanks in advance!

Note: its not the cabin air filter or engine air filter, I replaced them recently

ls430w140

Just few ideas on what It can be: O2 sensors, Spark plugs, Coils, Dirty injection system, dirty fuel pump filter, vacuum leak, dirty throttle body, injectors, fuel pressure dampers, faulty ECM.

TominPT

How bad is it? What kind of driving are you doing? How short/long are the trips? What is your driving style? Be as specific as possible. Everybody gets horrible mileage (10-12) with short trips in the city starting with a cold engine, driving like you are in the Le Mans race. . .

Edit- check tire pressure. AC alone will cost you 1-2 mpg depending on engine load.

Bocatrip

Agreed, The type of driving you do determines your mileage....How do you know what your actual gas mileage is without filling up the tank? Are you relying entirely on the trip computer on your car? I'm not sure how that will work without filling your tank. As mentioned, all city driving can give you very low teens 12-14 mpg which is quite normal. You need to be more specific on your driving style and what is your actual gas mileage?

GADawgs

Sorry but I don't understand what you are trying to say. What do you mean the "fuel range decreases by 2", Are you talking about the "RANGE APPROX" on the trip computer? Please clarify...

Have you actually calculated your average MPG? You'll need to fill the tank to do so. Fill it completely and note the odometer reading. Next time you get fuel, fill the tank completely again. Note the odometer reading. Divide the number of miles driven between fill-ups by the number of gallons of gas it took to refill the tank. What is that number? What type of driving did you typically do during that time? City or highway? Was your driving style tend towards aggressive or towards cautious?

BigBoomer

Far more likely to be a change in your driving than a change in the car at 85k miles.
What gas mileage are you getting?
Did you reset the average gas mileage reading and then see what mileage you get?

Rehzy

yea range approx, it decreases by 2s, meaning it consumes alot of fuel, I drive in the city I average about 15-17mpg

Rehzy

Oh man all those words give me anxiety lol, I'm going to replace the spark plugs and the O2 Sensor first, there is a hanging o2 sensor below somewhere in bank 2, also link for recommended o2 sensor?

nvwls

RockAuto denso with the wiring harness, just replaced mine
15-17mpg city is great

GADawgs

The RANGE APPROX tells you nothing about your actual MPG. How did you calculate 15-17 city MPG if you don't fill the tank?

EPA rating for city is 18 MPG for your LS430. If you tend to drive more on the "aggressive" side, your MPG will be lower. How do you drive? Are your tires inflated properly? Are you using the recommended fuel? Does your car have any codes?

May not be anything wrong with the car...don't rush to replace things unnecessarily.

TominPT

^ This. OP should be happy with 15-17 city. Nothing to see here.

Bocatrip

If you are getting 15-17 mpg in the city.. you are doing just fine..No worries.