Really bad gas comsuption
#1
Really bad gas comsuption
Hey there,
I have 2002 Infiniti i35 with 132,000 miles
I get about 16 mpg,
I get low gas indicator when I reach only about 240 miles after full tank
I changed sparkplugs, checked air filter, checked tire pressure, tried fuel injector cleaner
I don't have SES light and so I was wondering, it sounds like I may have bad oxygen sensor, but do SES light has to be ON if the oxygen sensor not working well?
Why do you think I might have such horrible gas consumption?
I have 2002 Infiniti i35 with 132,000 miles
I get about 16 mpg,
I get low gas indicator when I reach only about 240 miles after full tank
I changed sparkplugs, checked air filter, checked tire pressure, tried fuel injector cleaner
I don't have SES light and so I was wondering, it sounds like I may have bad oxygen sensor, but do SES light has to be ON if the oxygen sensor not working well?
Why do you think I might have such horrible gas consumption?
#5
I used to have misfire on cylinder four, I changed ignition coil and after that it disappeared. By the way, I think the problem started when I changed 3 front spark plugs, but it may be coincidence
#9
why is it bad to clean TB?
I brought some cleaner where I need to spray in the maniford from intake and at same time have about 2000 RPM
Also I brought Mass Air cleaner
I went to some good transmission repair place and I spoke with mechanic regarding my problem, he used OBD scanner to see if I have any pending/hidden codes and did not find any. He was clueless on what could be the problem.
I don't think that the problem is in stuff like dirty TB, manifold or anything else because I am getting 16 MPG instead of about 21 MPG and thats a HUGE Difference
I brought some cleaner where I need to spray in the maniford from intake and at same time have about 2000 RPM
Also I brought Mass Air cleaner
I went to some good transmission repair place and I spoke with mechanic regarding my problem, he used OBD scanner to see if I have any pending/hidden codes and did not find any. He was clueless on what could be the problem.
I don't think that the problem is in stuff like dirty TB, manifold or anything else because I am getting 16 MPG instead of about 21 MPG and thats a HUGE Difference
#14
#16
Thanks, what do you mean by recalibrate the TPS? I changed both O2 sensors, the one by firewall was pain in the ***, I think I bend the old sensor a little because it is really rusty there and really hard to get. I will let you know the results as soon as possible.
#17
K i maybe wrong about the recalibration. But i know if you have issues after cleaning the TB your suppose to reset the ecu or something along them lines. I found a thread that maybe pretty imformatible to you
http://forums.maxima.org/5th-generat...ly-yes-no.html
and this post sounds like the most reasonable way to clean your TB
http://forums.maxima.org/6856217-post40.html
Good luck. Im a 4th gen guy so i only know so much about the 5.5 since ive done a 3.5 swap. I dont know much about electronic wise with the 5.5 gen
http://forums.maxima.org/5th-generat...ly-yes-no.html
and this post sounds like the most reasonable way to clean your TB
http://forums.maxima.org/6856217-post40.html
Good luck. Im a 4th gen guy so i only know so much about the 5.5 since ive done a 3.5 swap. I dont know much about electronic wise with the 5.5 gen
#18
If your oxygen sensor has gone bad, it will throw a code. A bad O2 will kill your gas mileage, but it will also throw a CEL.
Is this 16 mpg in city or highway driving? How hard do you drive your car?
I know that even when my car is running 100% I can still get as low as 18 mpg in mostly city driving, but I drive pretty hard. I don't think a dirty TB will kill your mileage like this, although it might lose a few HP. If you were the one to install your spark plugs, are you sure you tightened them down to the correct torque specs?
Is this 16 mpg in city or highway driving? How hard do you drive your car?
I know that even when my car is running 100% I can still get as low as 18 mpg in mostly city driving, but I drive pretty hard. I don't think a dirty TB will kill your mileage like this, although it might lose a few HP. If you were the one to install your spark plugs, are you sure you tightened them down to the correct torque specs?
#19
I changed front 2 o2 sensors and mileage now even little worse. I got 15 mpg. Today I cleaned MAF sensor and will see if its going to help. I changed the sparkplugs by myself. I put in platinum +2 sparkplugs. Advanced auto parts said I don't need to gap them. Can you tell me more about torque specs? I just tighten up without any specs and as I mentioned earlier, it seems that the problem started after I replaced front 3 sparkplugs
#20
hmm, I'm also having a similar problem except mine isn't as extreme. I was getting 17.2 MPG for months but, keep in mind that I mainly drive in the city. I found out that I was over due for an oil change but, that only brought me up to 17.3 MPG. When I think about it, my gas milaege changed when I added an air intake and throttle body spacer. My sensor was reset and it settled at 17.2 MPG. I thought I should get better gas mileage? BTW, I don't race the crap out of my car anymore. So, that's not why my gas mileage is low.
#22
Yeah, all 6 plugs are changed.
But here is what I thought.
I have Bosch platinum +2 plugs and I read somewhere that there might be some problems because Bosch is not very compatible with nissan/infiniti. I ordered 3 NGK plugs and we'll see if it's going to help.
Has anybody heard about bosch been not very compatible?
But here is what I thought.
I have Bosch platinum +2 plugs and I read somewhere that there might be some problems because Bosch is not very compatible with nissan/infiniti. I ordered 3 NGK plugs and we'll see if it's going to help.
Has anybody heard about bosch been not very compatible?
#25
I just ordered knock sensor on ebay for $30
You think its good?
http://cgi.ebay.com/ebaymotors/ws/eB...m=370485524639
It says its made in Japan
You think its good?
http://cgi.ebay.com/ebaymotors/ws/eB...m=370485524639
It says its made in Japan
#26
is this possible with a 99 I30t manual trans as well? i think im getting crap MPG but i went from a 1.9l 4 banger to this and i seem to only get about 210 miles out of a tank. and with $50 bucks of premium only getting me a lil over 3/4 of a tank on my last fill up, thats no good.
#27
is this possible with a 99 I30t manual trans as well? i think im getting crap MPG but i went from a 1.9l 4 banger to this and i seem to only get about 210 miles out of a tank. and with $50 bucks of premium only getting me a lil over 3/4 of a tank on my last fill up, thats no good.
#33
i calculate mpg thusly: trip odo / how many gallons i fill up. if i was a stickler for checking my mpg, i would have a log book, but im not that guy lol. my mom has done it on every car she ever owned. that way she can see if she gets a big drop in mpg that usually means something is wrong.
ive had the car for almost a month now, and i do only work 5 miles away and the bar is about that far aswell, so yeah lots of short trips. hopefully this monday when i take a 2 hour trip to pick up parts for my el camino itll be better.
ive had the car for almost a month now, and i do only work 5 miles away and the bar is about that far aswell, so yeah lots of short trips. hopefully this monday when i take a 2 hour trip to pick up parts for my el camino itll be better.
Last edited by beermonkey9417; 04-02-2011 at 04:29 PM. Reason: added some stuff
#34
I have a 2002 I35 with about the same mileage. I just bought it about 2 weeks ago. So far I am getting about 28 mpg on 80% highway, 20% city.
Here are some thoughts.
Definitely gid rid of the Bosch plugs(they are crap). I also have an 00 maxima. It had Bosch plugs in it. I put the NGK Iridium IX plugs in and it made a big difference. Make sure you get the right temperature spark.
Do you have any mods to the air intake or manifold or are they stock? Have you seafoamed the intake or had injectors cleaned?
Considering the mileage and no codes, I'd be pretty concerned with a bad MAF, not just a dirty one.
If you have done everything you can think of to the engine and believe that it's running as good as it can, you may start considering problems with you rolling resistance.
I assume your tire pressure is good. Dragging brake calipers can definitely hurt your mileage. When was the last time you had an alignment? It won't make all the difference, but if you are out of aligment, you can really hurt you mileage (along with wearing out your tires fast). Tire type can make a difference also.
Just some thoughts.
Here are some thoughts.
Definitely gid rid of the Bosch plugs(they are crap). I also have an 00 maxima. It had Bosch plugs in it. I put the NGK Iridium IX plugs in and it made a big difference. Make sure you get the right temperature spark.
Do you have any mods to the air intake or manifold or are they stock? Have you seafoamed the intake or had injectors cleaned?
Considering the mileage and no codes, I'd be pretty concerned with a bad MAF, not just a dirty one.
If you have done everything you can think of to the engine and believe that it's running as good as it can, you may start considering problems with you rolling resistance.
I assume your tire pressure is good. Dragging brake calipers can definitely hurt your mileage. When was the last time you had an alignment? It won't make all the difference, but if you are out of aligment, you can really hurt you mileage (along with wearing out your tires fast). Tire type can make a difference also.
Just some thoughts.
#36
well i filled up with premium the past two tanks and my mpg has gone up 70 miles per tank. i was getting around 17mpg filling up with regular and now im getting around 19.5 mpg. yay premium!
Boo gas prices!
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#39
I went to my friend that had good odb tester and diagnostic tool and it revealed that I have problems with ignition timing advance #1. You think it could be problem to my gas milage? anybody knows how to fix it?
#40
Also it showed that I have problems with two O2 sensors
B1S1 and
B1S2,
I recently changed B1S1, so you think there might be something that affects both of these sensors? if both of them are B1
B1S1 and
B1S2,
I recently changed B1S1, so you think there might be something that affects both of these sensors? if both of them are B1