The spark plugs have been changed last week ... before the spark plug change, the gas mileage is still very low.

And the MAF sensor has been cleaned several time.

Anyway, we will change the MAF sensor tomorrow and let's see what will happen.

 

Okay, it's me again.

P1130 and P1135 is the code.
Changed the MAF sensor over the air box. Still, no change in MPG ... Still P1130 and P1135. Will change the B1S1 O2 sensor in the afternoon and see what will happen.

 

Alright, changed the MAF and 2 O2 sensors and the car runs smooth and obtain a good MPG again !~

Thanks, Lexmex and all other people who has helped me.

 

I get 20 mpg, I commute 75 miles one way to work.

 

awd or fwd?

 

AWD, I get about 16 local and at best now about 19 highway, although I haven't done a full tank of highway in a long time. I don't commute with my RX, it's my "baby"

 

Mine is horrible. I used 3/4 of a tank in 140 miles.

 

if you guy`s are not using premium fuel,that might be some of your problem. it call`s for 91 octane for engine performance, and durability. knock sensor retard`s the timing on regular unleaded. And not as much power,or fuel milage.

 

I am using premium gas (a full tank of it to go 130 miles).

 

MPG is horribly variable based soley on driving style, terrain and traffic environment.

My wife's '02 AWD had achieved over 30 MPG, that's not a typo, on several tanks when she's followed me while I've been driving our big diesel pusher motorhome. Top speed is 75 or so, and typical crusing speed is 62. Acceleration is rather lazy...at least for her. For me, the 5.9L Cummins is working it's heart out trying to move 32K lbs. from a standstill. For the 40 foot motorhome, when towing the Suzuki Grand Vitara we used to have, 0-60 MPH was 55 seconds. Slow is a poor description.

Sometimes she'd ask me over the FRS radio, "what's the problem?" For a while, I had a flaky oil pressure sending unit which would severly retard fuel delivery and turbocharger boost, but it was fixed at this point.

I'd have to reply, "nothing, this is a 6% grade and you've been seeing full-throttle since before we got to it."

Typical MPG in our Vegas home is about 19, but traffic here is truly bad and A/C use is mandatory almost year-round. The highest I've seen on the computer for a full tank was 32 and change. Had close to 600 miles on that tank....

FWIW, we've used only 87 octane, 85 at high elevation.

 

Granted, mileage will vary, but there is no reason at all that my 66 mustang with a 289, a 3 speed auto tranny, and more than a few performance mods, should be getting better mileage than the rx 300. Freeway is the only place the lexus' mileage is better, and only then because the mustang is turning over 3000 rpm's due to the 3 speed.

 

We have talked before about the IACV valve on the throttle body. Now some have removed the IACV valve completely to clean it out, this is also good to see how the valve is functioning itself. However, I wanted to show a little advanced step without having to remove the IACV to clean it.

Note below the blue arrow. This is running along top the air assist hose that connects to the engine block through some hoses and goes into the IACV valve at the end of the arrow.

 

Now I disconnect the air assist hose and you see the valve.

 

Then you want to shoot in the hole where the blue arrow is with carb cleaner or other engine degrease (actually I used something akin to liquid wrench that also worked well) and whatever you spray in there, will come out where the yellow air is pointing. For me, it was a little black at first and then clearer.

 

Now in the previous photo you can stick a small plastic cup or several sheets of paper towel underneath to catch the residue.

Next step is the this piece circled in blue. This plastic piece is where the air assist hose from the valve on the IACV valve goes to (do also clean that hose with some cleaner). Its function is to divert the air to the front and rear bank. This also gets dirty and I also had a bit of residue in here, too.