pedroj817

I am pondering cleaning the throttle body on my GX it has 88k on it. The reason for cleaning it and removing/unplugging the battery is because I am getting really bad millage 11 MPG. However I am hesitant to remove the batter for a fear of messing up the electrical system. Any advice to do this properly will be greatly appreciated. Oh FYI I have already ran 2 tanks of Chevron Fuel cleaner, the previous owner recently changes spark plugs, air filter is clean and tires are properly inflated. I think I read on this forum something about having the computer re-learn your driving habits.

ALAN553

The only thing lost when disconnecting battery, which eventually will always be done, is you have to reset radio stations, auto down and up on all windows and sunroof and maybe memorized seat settings. It also resets the ECU, but I don't think that is your milage problem.

pedroj817

Well what do you think could be the problem? I drive like an old lady keep it under 2 k rpms as much as possible.

danmm7

Oxygen sensors? Are they the original sensors? One or more of them may not be functioning well.

Spark plugs?

Brake calipers binding? Do you get lots of brake dust? Hot wheels?

Fuel injectors clean? Buy a can of BG44K and use it in a full tank of gas.

Air filter? Replace it if more than 7k miles old

andreys

I agree, I don't see throttle body being dirty dropping mpg that much. It can be 2-3 mpg, but not more.

My suggestion, if you have not done this before, taking your truck to a mechanic who can pin point the problem easily. It will take a mechanic far less time rather than you doing it yourself.

mann777

PEdro
This is a very simple job should not take more than 15-20 minutes at the top, provided you have the basic tools and some cleaning stuff for the MAF.
Here is the attachement, hope this helps.

pedroj817

Thanks Mann777, I will tackle this little project on the weekend and post any results later on. This Texas DFW weather is perfect for working on the truck.

RCsGX

I get about 11-12mpg city. My GX was a 1 owner and its always been maintained by the same Lexus dealer. I have pages of maintenance records that shes done so I dont know why my MPGs are so low seeing as its been babied and always well maintained.

I started off replacing the air filter w/ an OEM filter, cleaned the MAF senor and throttle body and did a Mobil 1 oil change. I had both upstream air / fuel sensors replaced w/ OEM sensors. I had Toyota do a fuel injection cleaning and a 4wheel alignment. While it was there I had Toyota check to see if my brakes were dragging and they said they weren't. I knew they weren't because I had 2 bad calipers on my Tundra DC so I know how it feels. The last thing to do was replace the spark plugs so I replaced them about 2 months ago w/ OEM Denso plugs and Im still getting the same crappy mileage. The only good thing is no matter how I drive it, like an old grandpa or like I stole it, I still get the same MPG. I gave up and dont even care about the MPGs anymore. It is what it is.

ALAN553

just curious, are you calculating the MPG's yourself or are you taking the word of the trip computer?

shyguyF

the way i calculate mpg is fill up the tank , drive about a few hundred miles and refill the tank , divide the gallon into the miles you drove. that is the exact result i do all time.
my car is 2006 and i usually get about 320 - 330 for 19 gallons. i forget to tell you guys i have denso ik20 spark plug on my car , it works better in mpg than the stock plugs.

RCsGX

I doubt those plugs give any noticeable difference.



And I calculate my MPGs by hand. If I went by the cars computer I'd be very happy as it reads 13.5pmg.

shyguyF

2 years ago when i want to replace the plugs i don't know where to start so i did search online and i found those plugs on densoproducts.com ( i really like denso stuff, my stock plugs is ngk not denso)so i called them and talked to the guy who helped me out with those plugs , so far i really like it i won' t come back the stock ones.
with those plugs it give you a smooth drive, better mpg and you won't disappointed.

ALAN553

They are both iridium plugs, I dont think you can measure any difference between them and ngk iridium plugs either on a dyno or by the seat of your pants. They are used interchangabley by most Asian manufacturers.

bauer26

I recently did a spark plug job on my wife's GX that included swapping the OEM NGK plugs with the Denso SK20R11. There was very little increase in mpg ( .5 - 1 MPG). That being said the only difference between the SK20R11 and the IK20 is the ground electrode on the IK is .4mm vs. the SK20's .7mm. The life expectancy of the IK20 is somewhere around 30k miles where as the SK20 will get ya 110-120k easy. The IK20s were meant for performance applications, not MPG. Even then they have only shown somewhere around a 1% increase in HP.

In the lifespan of a set of SK20R11s you'll have to buy 4 sets of IK20s. Not worth it!!

RCsGX

If youre happy thats all that matters. Personally I know they dont increase MPGs so theres no point in using them. If they increase MPGs Lexus wouldve used them from the start. Like bauer26 said, youll have to buy 4 sets of those to equal the mileage of 1 set of the OEM plugs, so of course the guy at denso*roducts told you to buy them.

I replaced my plugs about 2 months ago. My GX came with Densos SK20R11 and I replace them with the same set of Densos.