I know I need a KS but i can get 250-280 to the tank but so far this week its only been 180!!! and plus when I got my new tranny installed they fukd up one of my cranksensor and now my car starts and idles like sh*t! and thats going to cost another $150....Can there be anything else wrong with my car can get such bad mileage?

 

Tune up, don't drive so fast, air in tires....etc.

 

What is MPG? Not, "per tank".
Fill the tires with nitrogen?

 

I have one of the sensors that i'm looking to get rid of, brand new, never used. Not sure what name this one goes by, but it's part #31935-80X02 if it's what you need.

 

Bad gas mileage? Check.

Solution? Stop hotrodding the max. That's why my mileage is like it is.

It's hard, but keep it easy on the throttle.

EDIT: Replace KS. Any other codes?

 

Don't know if it helps But i do had a bad gas milage (about 150) per tank and the only code was "Coolant Temp Sensor" 0908 so i changed that and the milage went up for like 230 per tank (i think there is another thing wrong dont know) so check that. just my .02

 

dude, you stated you had a KS fault. Why don't you fix that first? Fix everything that you know is broken or not right and then post more. At this point we are not looking at your car and can not see anything obvious. We are going from your understands of your car. Again what is your gas mileage not per tank. We dont care per tank. The gas gauge is not detailed, it gives you a general idea. If you want a general idea then 230 /18.5 means 12.xx mpg.

If you dont fix the things you know thats wrong but you want more help, what makes us think that even if we told you what was wrong that you will actually replace it. I honestly hate people who complain about something when they know something is broken. Who is to say that your KS will not give you 150 more per tank. Say we list basic tune-up items for you to replace, i honestly dont think your going to do any of them since you haven't replaced the KS yet and i honest think i'm aleast 70% right on this, even if i don't know you.

I honestly am not trying to be a jerk about anything its just you state you have bad MPG and you want a fix for it but you didn't state what you have done in terms of tune-up. Its common sense to check plugs, filters and codes. You said you had a KS fault but why dont you fix that. When you do a tune-up and you gain MPG its not from 1 single part, its from a combo of parts.

I was getting 20mpg, in your terms thats 370 miles. Then i replaced my KS, air filter, spark plugs, fuel filter. Ran cleaning stuff thru my gas tank. clean out my Throttle body and did an induction service which is like seafoam to the car. Now i get 23mpg which is 425.5. each repair probaly gave me 20 miles more. So start with that. And post back, honestly there is no quick fix.

 

do you do all city miles? 180 miles/tank is pretty bad. make sure overdrive is on

 

Also, make sure your brakes are all working properly.
- brake calipers are not seized
- e-brake cable is not stuck

 

What's a good way to test if the e-brake cable is not stuck? My mpg has gone down a little bit (from about 25 to 22) and when i take my foot off the gas around 50-70mph, it seems like brakes might be dragging. I "rebuilt" the rear calipers by removing the piston and cleaning out and reinstalling, but this has not helped. Any thoughts?

 

um..my mileage is around 180 per tak as well (usually going no higher 3Krpm)
My trips are very short (just about 7mins one way). But i'm quite sure what to make of my rear brakes. Both rotors have rust on them and don't seem to have any pad wear(just got new ones installed 3 mo ago). I did some hard braking a couple of times, and theoretically, the rust should clan up, right?

 

crap guys then i guess im doing just fine im getting about 280-300 to a complete tank
i never let it get pass 1/4

I noticed when you control the throttle you are fine and the gas doesn't run out that fast

 

I've been getting 12-16mpg I don't really drive it hard at all.

 

to check to see if your rear brakes are locked up, jack up the rear of the car, put down the hand brake and spin the wheel. if it turns, they are not locked up. For HEYNOW, do this first and then pull up the handbrake and try again. if it spins with the brake up you have no pad contact. Front brakes, same thing except you jack up the front of the car, pull up the hand brake and put the car in nuetral. as for "rebuilding" the rear calipers, there is a little more to it than simply just open-lube-replace. if you put on new pads and sitll have rotor rust, there is no pad contact. so yours may be locked open. I will say this, if your brakes are locking, you would smell it at high speeds. change the KS, check your plugs for corrosion/oil/carbon (change if no good), clean your MAF sensor (spray is now @ pep bpys and costs $6), check your air filter and change your fuel filter.

 

If I got 180 miles to the tank, I would drive the Maxima off a cliff!

Tire pressure
Fuel filter
Clean throttle body
Chevron Techron
AutoRX to clean engine internals and ring packs
Spark plugs
Air filter
O2 sensors
Knock sensor
Crank sensor problem
Seafoam through brake booster hose to clean intake manifold
PCV valve
Clean EGR plenum/intake
Clean IACV
Change oil & filter
Decent gasoline
Stop driving it like you stole it
Consolidate short trips for errands into one longer trip
Walk, ride a bicycle, hitch hike, take a bus... stay at home



etc., etc.

 

Jesus... I get 380 miles per tank

 

Thanks dude, i'll try that sometime. As far as tune-up goes i've done the following:

Good Tire pressure
Changed Fuel filter
Cleaned throttle body
Ran Chevron Techron
AutoRX to clean engine internals and ring packs (2 much of a hassle in my opinion)
Changed Spark plugs (The old ones were extreemly carbon-fouled!!)
K&N Air filter
RAN Seafoam through brake booster hose to clean intake manifold
cHANGED PCV valve
Changed oil & filter (Mobil 1 Synth & Mobil 1 filter)
Always 93 octane
I never go above 3000rpm (on rare occasions)

Thanks for the brake suggestions!!! I'll try that as soon as i can!

 

How does that Auto RX stuff work?
I was looking at it. I have about 165k on my car. humm thinking about it.

 

www.auto-rx.com

You will need 2 bottles. The product is only available through the website.
Follow the instructions precisely, particularly the mileage requirements and when not to use synthetic oil.

 

when using Auto-rx your engine will tick louder. do not be discouraged. once you do the rinse phase it quiets down.

 

So then you do recommend.

 

man.. I thought it was normal.. my car has 143000miles on it no check engine light.. just changed the plugs and it has good power all around but the best I ever got was 206mpg and I always fill with premium about 16gallons per tank.. I better start doing some maintenence..

 

May have to check the brakes because I got new ones installed and they only lasted a month and about 1k 1.5 miles and alot of brake dust is coming off on to the wheels

Hmm this is alot to consider i guess i have to make a check list and do one every time i get paid or maybe two...I guess first up is KS and Crank and cleaning the TB then the fuel filter..air filter and plugs are done...oil needs to be changed in 600 miles...

 

I've read good things about it so I'm trying it in my car now. I've got 137,000 miles on my max, so I've got to do the 2 cycles. I'll prolly be finished with both cycles by the end of the month, because I've got a nice little drive back to Philly for Christmas. I'll let you know how it works out.

Right now I'm right around 24.8 mpg since I've owned my car. I know that's not bad, but I also know my engine is pretty dirty because I see it every time I look into it. I'm hoping to see at least a little increase in gas mileage.