billy boi

i have a 1993 lexus ls400 and it has about 155,000 miles on it . i changed both front o2 sensors and air filter . and i only get 10 miles per galllon . is there anything else i could do to try to improve my gas mileage . if it stays like this i might as well get a SUV . i am planning on changing the fuel filter and pcv valve . would that help ?

absolut

wow 10mpg is way to low. I really don't know what would cause such low gas milage. I usually watch my rpm's and try to stand around 2k or less to help with gas milage.

GRAND_LS 4

iTrader: (2)

Whatever you do, you have to do it quick before it ruins your cats. Sometimes the O2's can be off without throwing out a code. Any warning lights on? Does it run any differently?

sha4000

iTrader: (1)

do you smell any gas in the engine compartment or see any blue smoke coming out of your tailpipes?

spxChrome

With MPG that low it almost seems like the tank or somewhere in between it is leaking. I average about 19.2 MPG with my 93 LS which has 112K.

TJW98LS

iTrader: (1)

It is normal to smell gas at startup right?

GRAND_LS 4

iTrader: (2)

Not really. You get a different smell from the cats when they are cold, but nothing that smells like gas.

ychachad

Does your garage smell like gas? Then it may be leaking. EVen if you park outside, you have to see some gas stains and smell it for you to get such poor mileage. If it is leaking, stop driving and get it fixed. The car can be lethal. It can explode into flames, or you can even lose traction in the wet and spin out even if a drop or two, (yes a drop) get between the tyre and road when it's wet and you are turning.

Are you talking about 10 mpg with the A/C on, in really bad stop and go traffic? then it is normal. If you are talking highway at 65 mph steady, then something is wrong. It could be a combination of spark plugs, plug wires, distributor, MAF sensor, under inflated tyres, brake master cylinder locked, a stuck brake caliper, etc. Check all these and get back to us. I think it is time to take her in, hook her up to a diagnostic comp, and get pro help, even before you decided to change the O2 sensors.

sha4000

iTrader: (1)

one other thing. are you sure the odometer is working correctly? when i had my 91ls the odometer went and i didnt realize it until i took a long trip and checked to see how long the drive was

billy boi

no gas smell . no gas stains at parking spot . runs good . especially with new air filter on . no warning codes or check engine lights . good psi in tires . and yes , it is stop and go traffic alot with AC on full blast cause of 90-95 degree weather we're having . could that be the cause ? when i make my trip to philadelphia , i'm going to check to see if the odometer is correct .

billy boi

someone had brought this to my attenetion on the other lexus forum . that it could be either the cat or a brake caliper . i dont think its the catalytic convertor cause i passed inspection . but i do know that one of the calipers is like stuck . my friend was trying to pry it out so that it could move back and forth when applying the brakes but all it does is stay like in a locked position . but not on the rotor . like away from the rotor . could that be it ?

damon

If it was causing enough brake effect to cut your mileage by such a large % your steering would be pulling like crazy!!

Thissituation has to be kicking out a diagnostic code???

billy boi

true ! youre right . would me blasting the AC at full with stop and go traffic have any affect ?

spxChrome

Not a 10MPG effect.

kingkong5

I think it could. My wife took our 98 GS400 the last two weeks and we were only getting 13 mpg. She drives in stop/go with the AC full blast. I took it this week to work (I work 40 miles away, each way, all freeway at 75MPH) and got 23 MPG. She doesn't even really have a lead foot, so I can believe ~10 to 11 MPG for you.