ok before i get raped, i did search and found topics on this. and on all of them they talk about how much their car gets to the gallon opposed to offering solutions or things that may need fixing. i have a 98 gs-r and get about 220 230 on a tank. i've read that people get like 300 or 350 to a tank so something must be wrong. i have absolutly no idea what it could be, i changed my air filer, checked the spark plugs which were good and ran out of ideas there. also i dont drive like an *** hole, atleast i think i dont. i rarely take it above 4k but every once in awhile use vtec if anyone could help me out with things to check and what not it'd be appriciated thx

 

Maybe change your fuel filter, may have a clogged cat, faulty o2 sensor, etc. Many different things could be the cause.

I would do; cap and rotor, plugs (which you did), fuel filter, air filter (which you have done), check tire pressure, see if you can test your o2 sensor, have someone look at your cat. Then go from there.

 

yeh my CEL came on like a month ago and said faulty o2 sensor. but i also had a cracked exhaust manifold and i replaced that 3 weeks ago. and the CEL just popped back on last night

 

i use to be a manager at at autozone and the thing that will destroy your gas mileage the most is when the o2 sensor goes out. It tells the ecu if it is running to rich or to lean... well when it burns out the car thinks that it is running to lean and starts pooring the gas in the cylinders.... if you replace it and it is bad you will see a dramatic rise in horsepower as well...

 

but how much will a new 02 sensor run me

 

I've found that it can also depend on where you buy your gas at. Some places tend to have "better" gas than others. I know that Chevron, BP, and Shell all seem to be pretty decent places to get gas.

 

Well if your CEL is on because of 02 sensor, I would change that first and right away. Hopefully that would fix your problem. It wouldn't hurt to do everything else either if you have not done a tune up in a while.

I forget how much o2's are. It has been a few years since I baught one; I want to say around $80-100 but I could be way off.

 

Shell V-power is what goes into my teg i treat her with respek.

 

well our cars have two o2 sensors... they screw into the exahust manifold before the catalytic converter and a second one after the catalytic converter... the one in the exhaust manifold before the catalytic converter is the one that almost always burns out first... it usally cost 90 to 110... shop around for best price of course... p.s. dont get the universal one where you have to splice the wires yourself.. thats asking for trouble... get the oem one that plugs right in... autozone also rents out the o2 sensor wrench for free