I keep asking the same question becuase every time I could never get aid. Here is the situation...

1995 Maxima SE w/ 122K miles.
1 Owner before me, Dealership serviced ONLY.
ECU shows 0505 meaning no problems detected
I get about 220 miles of 80% city driving untill the gas light comes on.
I spend $30 every dam week.
Please help!

 

I don't know what to tell you. I just pulled the same code out of the ECU last night. I thought I might have at least needed to get a new knock sensor, but it does not say I need one.

However, I have heard that it will not cause the ECU to throw a code until the knock sensor is totally bad. I would probably just suggest getting one off of ebay or something and trying it out. Also, do things like replace the fuel filter(get one from the 350Z....it is bigger and supposedly works better.).

I am getting better gas mileage than that. My light doesn't come on until I reach like 360, but I am still debating on getting that knock sensor or not. I don't know?

What do you other guys think about his knock sensor? should he probably go ahead a get one, even though there is no code? I am voting yes, because it is a 95 and should be needing one right about now.

(fuel filter and plugs are easy and cheap, I would start there)

 

thanks man, i appreciate the feedback. I will try to get the fuel filter and plugs this weekend.

 

disconnect the sensor and see if you can tell the difference in the way car behaves. If not- it is faulty, change it.
How hard do you drive? Do your average shifts happen around 2500 rpm, 3000 or 4-5000?

 

You ought to be able to get all 6 plugs (NGK coppers) for about $12, and a fuel filter (I got Bosche for I think like $10).

Just look for how to install them, but neither are too hard.

Good luck trying this out, and let us know what happens. Hopefully, this will cure what is ailing your car.

Oh, and No problem on the feedback. That is what we are all here for...to help out.

 

disconnect the knock sensor?

and for the shifting...

its an auto and i got a heavy foot. i dont floor it at every light but i go about 40-45 in the city and sometimes show off the 190hp at those red lights at 3am

 

i will check tonight or tomorrow about my shifts... but if i recall correctly its about 3k.

 

I took her out for a spin.. and it shifts at 2.5k flawlessly. I mean i love this CAR! The ride is smooth as hell, if you gun it... it responds like it got a dam rocket engine and overall i couldnt be any happier.

Also i checked the tire pressure and it perfectly meets the manuals recomendation.

I don't think its the knock sensor and will get the fuel pump and plugs in a day or so...

 

Check your tire pressure/wear, air & oil filters cause those can contribute to bad gas mileage. Also, try a bottle of Valvoline's Fuel System Cleaner the next time you have to fill up. I used it on mine and noted that it works wonders. Good Luck.

 

I have the same problem, 130k miles, and i get 220 on a full tank. I'll be trying some of the said solutions and willl report back.

 

Had oil change 1 week ago, air filter and oil filter changed.

Tire pressure is perfect as i mentioned above.

I have 2 diff fuel system cleaners ready for next fill up. (1 on empty tank and 1 on full)

Also have a can of RestoreUSA ready for use before fill up.

I will drive this tank on O/D OFF (light on). And will report my progress....

Also Pasty let me know if you come up with anything.

 

why would you drive with the overdrive off? maybe thats why you got such bad gas mileage, fourth gear is there for a reason

 

I am getting around 290 with od on, I am due for an oil change though, and need new spark plugs.

 

what ****es me off, I get 270 for the first 3/4, 30 on the last quarter

 

i also get about 200-220 mpg. I also tend to drive about 40 through the city, and occasionally open up the VQ when I think no one is looking. Im a little above 1/4 tank at 190 miles...I changed my plugs two weeks ago, changed oil and filter then too. The air filter only has 2k on it. Maybe a fuel filter change is needed. My EGR is throwin a code, does that affect gas mileagE?

 

220! Man, that makes me feel good, that's got to be sub-14 mpg. I think my 17 city sucks. I've done pretty much all that tune up crap with little or no results. I get an 0505 code, so my car thinks its fine, but what a pig. The low end pickup is a dog. I have to bury it to get anything resembling rapid acceleration.

A local tech said I would lose as much as 20% mpg due to the winter oxygenated fuel, but we've shifted over now and I don't see any change. I drove a bit of freeway and squeaked out 19...woohoo! The tech also said the maf could be reading wrong, but after replacing plugs, filters, adding intake, y pipe, etc., I'm tired of troubleshooting through replacement and a maf or coils aint cheap.

Anyone have any thoughts on the possibility of maf or coils giving retarded performance/ bad mpg with NO codes?

 

i get about 320 at 14 gallons, 380 at 16.5 gallons with 50/50 hwy and local driving. 23mi/gallon.

i'm running mobil 1 supersyn 5w/30, oem nissan filter, k&n recharger kit on the jwt filter, cleaned throttle and IAC valve, good condition NGK 1 step colder spark plugs, brand new knock sensor, good o2s, good engine coolant temperature sensor.

maintance > modding

 

my rear o2 sensor is throwing a code, along with my EGR valve. I figured my o2 sensor would affect it, but i read before that if the front two are working, that the rear sensor wont affect gas mileage. im not sure about the egr valve. ill look into it this weekend though

i also have mobil 1 supersyn, just changed it about 1k ago. I'm gonna look into replacing the fuel filter this weekend. I agree with the maitenance > modding. It's just been so dam expensive to keep up with it. I've changed the knock sensor, the two front o2 sensors, flushed tranny, new brake job that still squeaks, and now its like i get a new code to replace the one i just fixed. but when she's finally running smooth like she should, ill be happy

 

What exactly does that have to do with anything? When he said what rpm it shifts, he was asking about your driving habbits. If it shifts at 2500rpm or below it means you don't drive hard which should make your fuel economy better.

 

and you need fuel filter, not pump.

 

Well i just fuled her today and added all those fuel cleaners i bought. I fuled to 15.6 gallons and had 210 miles on that tank. Thats when the light came on. Thats under 14 miles/ gallon!

I drove that tank with OD on (light off).
This one i will try with OD off (light on).
And when I was asked about the rpms i thought it was a relation to the milage, since my old car '92 legend, had an rpm problem with late shifts.
Anyway well c what happens...

 

On that note, I think im gonna go take some pics.. and get a car domain page going...

 

O/D should be turned on when driving 40mph or higher only. It won't change your ga mileage at ALL if you drive with it on or off the whole time. Those fuel cleaners you bought, you just threw your money away.

 

Thats not neccessarly true. I heard about, and seen the cleaners working, so I dunno where ur getting ur info from.

 

I've always been too scared to go to the gas light.
about how miles can i get when the light comes on, and about where is the needle on the gauge when the lights comes on.

 

you got about 2 gallons left when the light comes on

 

correction.....1 gallon when the light comes on. I have run out of gas trying this! ha ha.

You have a little more maybe if the light first comes on and doesn't stay on, but when it stays on, you had better be pulling into a gas station, because according to most people's mpg, you have about 20 miles.

 

I just got my new fuel filter, and what do you know, no instructions. how do i install this?

 

How do you disconect the sensor other then pulling the plug? is there a fuse for knock sensor?

 

I had my light come on today, and this was wen i was in line for a car wash... well i got a little scared, but manged to get to the station...and it filled up 15.6 gallons! thats 3 gallons left.