'03 Matrix poor gas mileage

[zieglermaria]

I just bought a 2003 4WD Matrix and have consistently been getting 28-30mpg. suddenly my gas mileage has dropped down to around 18-21mpg and the car is feeling more sluggish. My local dealer says that there is nothing he can do as the check engine light has not come on (it still works..... it illuminates upon starting the vehicle)

Anyone got any ideas?? The total mileage on the vehicle is 40K.

[mistamatrix]

Do you get gas from the same station all the time?

[zieglermaria]

Typically I buy my gas at the same station. Since noticing the drop in gas mileage I tried running down to almost empty, adding cleaner and filling up at a different station. I have tried using gas from different stations since then but have seen no improvement in fuel economy. Also I am now noticing a drop in performance , especially on hills.

[Zrain]

yell at the dealer to take the car in and pull fuel trim and other information.. they shouldent tell you to go away like that... thats a load of BULL. im willing to bet ur runing insane amounts of Fuel Trim.. u might even have a shot O2 Scencor. ur discribing a CLASIC "My ECU has its head up its ass" Syndrome

and if they try and charger you for the dignostic.. tell them to go "F" them selves.. and go to a difrent dealer.. also threten to write a leter to Toyota Corprate. basicly.. they just need to check your fuel system to see what computer related shit is sending the wrong signals.

[Hajoca]

GOOD FOR YOU!!

By keeping an eye on your fuel consumption you spotted a problem before others complicate the mix!!

My friend noticed same, but ignored it... then front cat went due to higher operating temperatures and the O2 sensor died also.
So that cost big bucks. All caused by a 'loose' Air intake sensor.

Anyways, the symptoms described should prompt the dealer or yourself to check the air intake... is it clogged??

(not just filter but intake snorkel assembly, like a rodent nest, squirrel food cupboard, or it injested some other debris)

Do you have any loose / leaking vacuum lines?
loose sensor plugs?

and lasly is EGR valve stuck?

The Stealer ought to have gone through all of that!

[Blue636]

I'm sure that this has all been great advice, but I'd also like to add that you should be using the lowest possible octane you can get away with. I can use 87 octane with no problem. Also, I'd like to add that you should check your tire pressure every week or every other week... believe me, this alone can make 3-5mpg difference! Also, use the recommended viscosity oil for your car - it won't make a huge difference but it's definitely not going to hurt it. I'd recommend Mobil 1 5w-30.

The single biggest factor in your average miles-per-gallon is the way you drive. Don't accelerate too fast and don't stay on the gas until you have to brake. That is, whenever you are anticipating a stop, try to let it coast for as long as possible before braking. You should have no problem losing speed if you have proper tire pressure since the Matrix doesn't have much engine braking at all.

Other than that, if you keep everything in good order and you drive sanely, I'd have the dealer check it under warranty because you could have a problem.