Check Engine Light Options

[hs2g]

My check engine light is just showed up about 2 days ago while I was driving. I thought it was my sparks plugs and maybe the car needs a tune up since it already has 75000 miles. So I called my local toyota dealer and they said that a tune up or spark plugs have nothing to do with the light. They said it was either my sensors, exhaust, or fuel. They want $75 up front too check it out and maybe some more if I want them too fix what is wrong.

I don't want to spend $75 just for checking what is wrong, but I can tell you I notice a change in gas mileage. I just pumped my gas to half tank yesterday and I only drove for maybe 30 miles on normal condition (shift at around 3k RPM) My gas went down to 1/4 tank. Thats crazy.

So does anyone have any idea what could be wrong?

[jayi12-15psi]

yes, but, lets remember that they changed codes in the mid 90's from obd1 to obd2, so depending on the year of the celica, you might not have obd2, and if you don't have obd2 autozone can't check your codes, at least not in st. louis, you can also buy code readers off of ebay. think about it, even if a code reader costs $250, you can use it over and over, and never have to pay toyota for a $75 dollar diagnostic everytime something goes wrong with your car.

but I do think that they changed it to obd2 in possibly 96? at the latest 98