[93cavdemon]

hey guy i jsut wanna know any one got any susgestions as to why im getting bad gas milage??? i tryed alot of things high test changed fuel & air filter layed off the gas for a tank any other sustestions? im gettting 11 thats worse then my dads 2003 avalance that 8cyl and my nons 6cyl blazer bty i got a 2.2

if i cant fix this im retireing it by graduation for hopefully a vw golf gti

 

[nemesis25]

Bad O2 sensor, dirty injectors, dirty fuel filter, Bad MAP sensor, bad coils/plug wires/plugs, worn out exhaust system ( bad cat or muffler, or even an exhaust leak), etc... The list goes on :lol:

 

[93cavdemon]

i changed the cat you think if i put it on diagnotics they could find the prob and i could fix it my self and the cheack engine light dosent come on at all so i dont think it owuld be a bad o2 sensor

 

[nemesis25]

I had a bad O2 sensor, and my check engine light never came on. An O2 sensor should be changed every 80k, (50K miles) I believe. Hows the rest of the exhaust? How long has it been sense you changed the fuel filter? Also dirty oil will effect fuel efficiency. Yes putting it on a diagnostic machine might help.

 

[Six_Shooter]

Yeah my O2 sensor also was bad, and never threw a SES light, in my case however, the engine would not rev above 3000 RPM, but I had a severe failure of the O2.