I know there's been 112,241,242 topics on this, so please bear with me guys, I just wanted to throw my personal issue out and get opinions more targeted to my specific problem.

So anyway, for as long as I can remember in my usual routine I average 290-300 miles per tank, been that way since I got the car almost two years ago. But anyway in the past 2 months, I havent really changed my routine but my average mileage per tank has dropped to like 240-250. Not a hugely severe drop, but enough to make a difference at the pump and my wallet and it's been consistent enough that something's most likely up.
Sooo I know I should probably clean my EGR and maybe dump some fuel injector cleaner in my tank and all that jazz, but what are some other things I could do to help rescue my car's mileage No holds barred I'll clean anything and replace anything I need to.

 

OIL (what you running, brand, thickness?)
Check if your getting any codes, do you put gas at diff't stations, PREMIUM?

-CHANGE and DO TUNEUP
SPARK PLUGS NGK VPOWER
AIR FILTER
02 Sensors (if your getting codes, or if you'd like)
FUEL FILTER
TIRE PRESSURE
RESET ECU

I'd avoid fuel injectors, but that's just me. Check all that, and see if your car is running fine, maybe its the gas station, or knock sensor. How much miles your car has?

 

About 126,xxx.
I always put premium in it, usually Chevron's premium unless there's no Chevron around and I really need gas.
God I hope it's not the knock sensor.

 

check your codes. i got a new KS (trust me it's worth the money now bc you'll end up paying for a lot more in gas) and i cleaned my iacv; this got me from barely 300 miles a tank to 380-400 with mostly city driving. and read the others posts about gas mileage and take 5 minutes to read through them. they all say the same thing.

 

Change your oil and spark plugs if you havent done. Also change your air filter. If you have the money put an injen cold air intake. Power and better gas Mileage and always put Premium

 

wow, thats like twice as much mileage as me.

 

Crap.

The gas gauge has the needle about...2-3 mm below the halfway point, and i'm at 152 miles since I last filled up. I won't even make 300 at this rate! I rarely use my AC, actually this time around, I haven't used it since the last fill up for experimental purposes. I think my mechanic turned it on the other day, but not sure how long.

Another dumb question: How much does the AC affect gas mileage?

I think the KS is the solution but I can't spend another dime on my car for a while. New fan belt, tune-up, new exhaust (from cat-back...rust destroyed it), new starter, new exhaust bindings (which was freakin waste of money since I got my exhaust replaced anyhow). How much would replacing the KS cost? Sorry for the noob questions, this is only my second post, AND i'm on 56k.

 

If you rarely use AC, don't worry about its effect on your mileage.

Check your ECU codes. Simple procedure in the stickies for that. If you see code 0304, that's your KS (that code won't activate your CEL). If you don't, there's a slight chance your KS should be bad, but don't worry about it unless you try everything else and then run out of ideas.

I got my new KS for just over $98 shipped from eBay. I replaced it in about 15 minutes with a click-type torque wrench, foot-long socket extension, a 12mm universal articulating socket, and some tough gloves to keep my hand from getting chewed to bits from jamming it into where the KS sits. HUGE improvement in mileage and power, that's for damn sure.