im new to the group but i need some advice on whats makin my 99' olds alero burn sooo much gas,, ive replaced these items within the past 6 months in no particlular order to try to fix the problem..
fuel pump, fuel filter, head gasket, thermostat, water pump, serpentine belt, catalytic converter, o2 sensor in front of catalytic converter, .. ive had 2 diagnostics and nothing shows up...yet im still burnin a ton of gas and i only live 10 minutes from work so theres no heavy driving goin on..i need some advice badly on how to fix this...

I didn't see sparkplugs or wires in the list??? And what temp thermostat did you use?

i did change the spark plugs and wires about 6 months ago hopefully thats not the problem..i dont remember the brand of the thermostat i used but i can find out..also my vehicle tends to run higher than usual..but i was told thats the way GM vehicles are.. i dont know think thats true

which engine? air filter? someone check the fuel pressure? what exactly do you mean by diagnostic?

by diagnostic i mean i had firestone put it on the machine to see what was wrong since my check engine light keeps comin on even after im constantly replacing parts..

What code(*) do you have? If there'* an Autozone nearby you can get them checked for free.

blackarrow i tried the autozone thing and of course they give a list of things that could b wrong never pinpointing the exact problem..

Well, I can think of a few things that would cause the engine to idle higher than normal; vacuum leak, skewed ECT sensor, bad IAC motor. Which engine do you have? 3.4L?

ive just replaced this 02 sensor and its still burnin alot of gas,,,yet when i put the car on he machine it says nothin is wrong but a person knows their vehicles so something has gotta be wrong with it..

If its throwing check engine lights, you need to get us those codes FIRST. We can't do anything else until we see the codes, and advise from there. Otherwise we are playing guessing games all day long.