pls help my maxima consumes about 10 MPG even without AC on and with AC its far lesser.

Before i had P0135, which i have fixed. i bought a cat converter and O2 sensor. after fixing, the codes went away.

Now i have P0505 and P0180. i know they both have nothing to do with fuel consumption.

A mechanic said i should change the nozzles cos sometimes after long drive and restart, it releases white smoke for about 5 sec before regulating.

pls advice cos i love this car cos of the speed and great power

 

besides MPG does it suffer from any kind of performance issues?

Any lack of power?

Did you use either a Bosch or NGK O2 sensor?


Have you checked what your voltage is when idling on your primary O2 sensor?

Should switch rapidly between 0-1.0 V back and forth

 

the O2 sensor is bosch.

yes i have little jerking intermittently but not frequent.

No loss of power. car speeds perfectly and over consumes fuel perfectly

 

a bad fuel pump can cause this too, i've seen it happen to other cars before.

 

knock sensor

 

U mean bad fuel can cause high fuel consumption?

 

No, the fuel pump.

 

P0180 Tank Fuel Temp Sensor

Component Description

The fuel tank temperature sensor is used to detect the fuel temperature inside the fuel tank. The sensor modifies a voltage signal from the ECM. The modified signal returns to the ECM as the fuel temperature input. The sensor uses a thermistor which is sensitive to the change in temperature. The electrical resistance of the thermistor decreases as temperature increases.

DTC detecting condition:

An excessively high or low voltage is sent to ECM.
Rationally incorrect voltage is sent to ECM, compared with the voltage signals from engine coolant temperature sensor and intake air temperature sensor.
Possible cause:

Harness or connectors (The sensor circuit is open or shorted)
Fuel tank temperature sensor may be faulty

and your p0150(Bank 2 Sensor 1) is for the primary oxygen sensor(the one you see in the exhaust manifold when you pop the hood) your O2 sensor could be directly related to your fuel consumption. After all the O2 sensor(especially the primary) helps the ECM to determine how much fuel to inject.

With all that said you need to fix both those issues but I'm sure the O2 sensor is why your MPG sucks right now.

 

Which O2 sensor did u change?

 

He fixed p0135 which is Bank 1 Sensor 1(primary O2), he now has a p0150 which is for his Bank 2 primary O2 sensor. Assuming he put them in the correct location...

OP: do you have a cali spec or federal emissions?

 

I had an argument in another thread regarding O2s. I know that the 4th gen Maxima ECU uses only one O2 sensor to accurately measure air/feul, the one just behind the radiator in the exhaust manifold.

I surmised that the same is the case with the 5th gen.

If the OP replaces Bank 2 sensor 1 (that is THE O2 sensor IMO.......all others are secondary) and his mileage improves, this will validate my point.

Here's a link to the other thread.....

http://forums.maxima.org/8633210-post389.html

 

are you trying to make a point to me lol? I never said anything about which O2 sensor controls the fuel/air ratio(I just said the primary). The OP simply stated that he changed bank 1 sensor 1 and THEN got a code for bank 2 sensor 1. His MPG is still bad though because he has yet to change his Bank 2 primary sensor(this could help your argument).

Now as far as I see it you have 2 banks each has a primary and secondary(this is from an individual bank standpoint). Now from an overall engine standpoint the Bank 2 primary could be THE O2 sensor(someone has to be king right...lol).

I am assuming you mentioned all this for wealth of knowledge or just so the OP can do some good ol' reading/searching.

I clicked on the link you gave but it was only for a single post...

EDIT: seen which thread it is, I've been reading that thread on and off some.

 

thanks all for ur input. i made a mistake. the other code is P0505. i.e the iacv. can it cause a poor MPG?

 

i did a pressure test on my fuel pump and it returned okay. pls help

 

I know. You pointed out which one he changed so then I pointed out, for everyone to see because it's a forum, the the other O2 is the Primary king.

Yes


Exactly. Trying to help and learn something along the way.


It's a HUGE thread. TC-W3 is AWESOME. Here's the page of that thread where me and other got into O2s;

http://forums.maxima.org/general-max...ml#post8633210

 

In summary, change the OTHER O2 sensor. IACV wont affect mileage that much. When you do change the O2, you should notice an immediate improvement in engine responsiveness. Instantly more peppy. If that is the case, then as you run the miles you will see your mileage improve.

 

you have poor gas mileage and smoke on start up along with slight hesitation because one or more of your fuel injectors are leaking. Find the leaky injector and replace it pronto.

 

thks man. my mechanic said something along that line.

 

If your injector is the problem, rather than replace it, try lubricating it.

This thread (at the bottom of this post) details adding 2 cycle oil with TC-W3 to your gas tank. The main benefit is that it lubricates your fuel pump AND injectors.

Maybe your injectors is sticking/sluggish because you do say that the white smoke does eventually go away.

It's worth trying, cost pennies (relatively), and you don't have to take anything apart. Pour a couple of ounces in your tank and see what happens.

I still think you should change the main O2 sensor as well.

http://forums.maxima.org/subscriptio...n&folderid=all

 

thks man. the challenge im having is that im in africa and most of these things arent available. My mechanic once suggested i poor a bottle of thinner in the tank to clean the nozzles. how safe is this?

also why should i change 02 sensor when there isnt a code for same?

 

Don't do it! Do this instead (if you can find TC-W3 out there somewhere);

http://forums.maxima.org/general-max...troke-oil.html




O2 sensors get tired. They do not throw a code, but your car suffers. Lack of power, bad gas mileage. etc I would sugget that you do this after doing a thorough tuneup, spark plugs, air and feul filter etc. If you still find the car to be sluggosh after the tuneup, replace the primary O2.

The 4th Gen Maxima uses the front O2 sensor behind the radiator, inside the exhaust manifold, to fine tune air-feul ratio. That is the ONLY one to worry about changing. The others are all secondary to that one. I beleive that the 5th gen maxima is the same way.

 

Which part of Africa are you in?

 

where is the fuel filter located in maxima? also what are the primary sensors?

thks

 

On the 2000 and later maximas, the feul filter became a part of the feul pump...supposedly non-maintencne now

For the primary O2 sensor, look here for Bank 2 sensor 1

http://forums.maxima.org/8633197-post388.html

 

ok. now the fuel treatment u talked about isnt available in nigeria or ghana. my air filter is dirty and would be changing it anyway. in the absence of the fuel treatment, i can just go ahead to replace the injectors?

 

i also learned that thinner has Toluene and Xylene only as ingredients and these are the main constituenets for Octane booster our cars need

 

I just noticed your intermittent jerking comment. Maybe you have a bad ignition coil.
I am going through that myself right now. One of my coils, don't know which one, only starts acting up when the engine is hot. I've gone all through the threads here and I am finding that I will have to replace the coils one by one until the problem goes away.

 

lets see how it goes. are u based in the state?